This appears to me to be a reasonably comprehensive list to cover most of the essential HPS syllabus.
What worries me about HPS is that it shouldn't be studied just on its own, as I see it traditional philosophy ought to be a prerequisite or studied concurrently. As you'll note, this list doesn't include those texts.
Traditional philosophy puts the ethical and logical thinking structures (reasoning processes) in place - it supplies the framework to make HPS more understandable and cohesive.
(In my opinion, both subjects are increasingly important in the modern world as developments in science, engineering and technology generally have reached such a stage of development that we cannot afford for too much to go wrong - the consequences are too great. Both phil. and HPS put things into perspective and thus can have a stabilizing influence - that is if we take them seriously and apply them properly.)
Oh heavens, there are so many. Let me think about it and I'll post a few titles. It would be easy to list lots but for those studying HPS it's important to make them as relevant as possible.
The 'trouble' with philosophy (actually more its beauty) is that it's such wide, diverse and interesting subject that it's dead easy wander off into one of its many branches and then get sidetracked. As it is, many professional philosophers specialize in one of these branch fields (not that that's a bad thing as they've already learned the prerequisites - shortcuts don't usually work here).
Although I've studied philosophy I'm not a professional philosopher (I'm in technolgy) so it's very important that I try not to mislead anyone (actually philosophy teaches you to think like that).
Irrespective of any texts that I would recommend, there are two things you should do: (a) consult the syllabuses of traditional university philosophy courses, and (b) either talk to a mainstream philosopher or professional university lecturer in the subject about suitable texts or even about doing a short course in the subject (that's if you are already doing HPS).
(Let me stress, identify mainstream philosophical strands first, learn from them so you don't waste time.)
Let me add these points, I've always been involved with technology, science and engineering - technology has brought me my bread and butter but my studying philosophy and HPS has profoundly altered my perception of technology per se - and for that matter the world in general. In many ways it's made me a better human being simply because it teaches one to view the world from multiple perspectives and to try and think logically. (Mind you, that doesn't always work but you at least know when you've screwed up. Philosophy is a very persistent and recalcitrant rose-colored glasses remover.)
Like many obsessive techies, it's easy for me to get fixated on my own specialities at the exclusion of almost everything else. Philosophy has the marvelous ability of regularly kicking me off my pedestal back down to earth.
As such, I reckon both philosophy and HPS ought be compulsory short courses for both scientists and engineers at university.
I've had two attempts to post a list and each time it was deemed too long even on the second heavy edit (perhaps I'm being penalized for too many long posts lately as this one had a considerably shorter byte count than others I've posted successfully).
Anyway, it was mostly a reedited rehash of stuff that I've posted previously with a few new additions (rehashing it saved considerable time over starting from scratch). By cutting it even further it won't serve its purpose. When I've a moment I'll restructure and re-post it.
Here's my promised list (note it's only a rough guide). As mentioned, I couldn't post earlier versions as they were too big. Even this new rehash (which was already rehashed from much older posts) is too big, so I'll post the first two thirds now and the remainder later. What's missing (compared to my initial attempt) are large sections of my commentary. For additional details use Wiki (these books are well known, hence they all should have entries). Most are out of copyright so you can download them from the I.A. (Internet Archive).
1. The Republic (Book 1 only)—Plato Begin study here; it's an excellent intro to formal argument (v. important), as it's the basis of arguing things out in logical ways. It's a dialogue between the philosopher Socrates and a sophist Thrasymachus about the meaning of justice. It's also fun to read, watching Socrates demolish Thrasymachus' selfish stance of 'every-man-for-himself' in logical sequence is like watching a chess game between a master and a cocky arrogant rookie. The book's passed the test of time, it's still in print nearly two half millennia after it was written. Use Jowett's translation, 1892 ed will do. Jowet's info: https://en.wikipedia.org/wiki/Benjamin_Jowett
2. Last Days of Socrates—Plato (Read only if you've time.) It's important in the grand scheme of Greek philosophy and the fact that Plato was affected by the execution of Socrates (his teacher).
3. Nicomachean Ethics—Aristotle (Likely too long now but essential later). Any Aristotle text is worthy of study, he's a giant in the field, his influence is still stamped all over Western culture today. Phil. is incomplete without studying him. The book's deals with ethics and how people should live their lives.
4. Meditations on First Philosophy, & etc.—René Descartes Very influential book. Initially, just read Discourse on the Method, it's about finding the truth, especially the sciences. Here, you'll find the famous phrase "I think therefore I exist/am". It also turns up in the 'related' Principles of Philosophy as Cogito, ergo sum. If you advance further, you'll be taught about breakdowns in reasoning/faulty logic and Descartes isn't immune to them either. One of his logical steps is a misstep and is famous for it—no, I won't tell you what its is.
5. Sir Francis Bacon—Rather than give specific references just get his collected essays (they're all short), select any relevant tiles to read.
6. The Leviathan—Thomas Hobbes. Herein Hobbes addresses statecraft, society, civil power government (actually very important). Written in the aftermath of the English Civil War when such matters were still raw and fluid. BTW, our modern understanding of the word commonwealth comes from Hobbes, the book's full title is: Leviathan or The Matter, Forme and Power of a Common Wealth Ecclesiasticall and Civil.
7 & 8. Two Treatises of Government | An Essay Concerning Human Understanding—John Locke Locke is an English empiricist Enlightenment philosopher, his ideas had a strong influence on governance structures in the U.S. Locke was an early epistemologist, so his words are well chosen and noted for the fact. He had a very influential effect on later philosophers. The Two Treatises of Government deals with civil society, one's rights, property and contracts. An Essay Concerning Human Understanding deals with empiricism, fundamental ideas, innate concepts and notions such as 'color', 'good' etc. Locke had a great influence on philosophers such as Hume, Kant, Berkeley, Moore and many others.
9. The Prince—Niccolò Machiavelli He gets a bad press although he doesn't deserve it. It's questionable that he was truly 'Machiavellian' himself. Simply, The Prince is sound practical (worldly) advice to a prince about how to conduct oneself and how not be screwed by one's enemies (be wary/aware of likely enemies, avoid situations that could lead to one's dethronement). It's a very short book, just a few hours to read.
10 & 11. On Liberty | Utilitarianism—John Stuart Mill. Both books were highly influential and still are. On liberty deals with a theory of liberty—re liberty itself, also concerning political rulers, tyrants and tyranny. Utilitarianism is about utility, the notion of the greatest good for the greatest number, it still underpins the philosophy behind the running of most modern cities/states today.
12, 13 & 14. A Treatise of Human Nature | An Enquiry Concerning Human Understanding | An Enquiry Concerning the Principles of Morals—David Hume It is impossible [I almost said 'almost'] to cover these works in a couple of sentences, so I won't. At least you should know about them and what they are about. Hume is a Scottish Enlightenment philosopher and much more. His works are uncannily modern and prescient nearly 300 years after they were written. He's hugely relevant to philosophy, science and culture in general; a true giant in the field. Like Locke, he was not a believer in innate ideas but rather that they come from experience (like George Berkeley's Tree in the quad arguments). He's the principle founder of philosophical induction and much more.
15. The Social Contract—Jean-Jacques Rousseau This is a great work (and fun to read). The most famous opening sentence of any philosophical work likely ever written, ancient or modern, is at the very beginning of Chapter 1: L'Homme eft né libre, and par-tout il eft dans les fers.—Man was born free, and everywhere he is in chains. Words of great influence and they were in fact so. Those words were much the truth in 1762 and they're still pretty much true nowadays (unfortunately)!
It's Rousseau's most famous work. He discusses political society and conjectures all people will be free if everyone equally gives up certain rights then all accept the responsibility and obligation thrust upon them in equal measure for their own collective governance. Here, he posits the notion of the The General Will of the Citizenry, it's this that should drive legislative government. The General Will should always hold government to account, especially when it exceeds authority or legitimacy. The Social Contract was revolutionary at the time (1762), only 27 years later the French Revolution took place and Rousseau's ideas, at least in part, were influential in causing the foment that led up to it. It changed governance for the better and today we're its beneficiaries (at least so in democracies).
16. Critique of Pure Reason—Emmanuel Kant I'm hesitant to mention Kant because he can be so obscure. The trouble is that he's so influential. Kant deals with knowledge, reason, human reasoning, and empirical reason. One cannot ignore Kant or does so at his/her peril, (perhaps this book is better left until you've a fuller grasp of the subject).
17. Principia Ethica—G. E. Moore (George Edward) Prof of Phil., Cambridge, UK at turn of the 20th Century. Since it was published in 1903 Principia Ethica has had a huge influence on philosophers and still does (incl. yours truly, it was one of my early texts). ;-) It deals with the notion that certain ideas and concepts cannot reduced into simpler terms because they're already irreducible. 'Good' or 'bad' can't be reduced further as we've no way of measuring them. We know/learn what 'good' means intrinsically, so too 'very good' but we cannot measure the amount of 'good', nor can we measure how much 'very' adds to it. Here's another case: normal sighted people and those who've gone blind later in life know the colour 'yellow' as they've physically seen and perceived it, but no amount of trying will convey that perceived notion to a person blind from birth (they'll learn a conceptual understanding but can't actually perceive color as the sighted do). There's much more to Moore too: moral philosophy, etc. He was a trendsetter for much of 20th C. philosophy.
18. The Problems of Philosophy—Bertrand Russell Russell was one of the last great polymaths and a social reformer, philosopher, logician and much more (I remember him on TV when a kid). The Book discusses past philosophical problems and equates/restates them in his terms. He questions, discusses, countenances and argues over subjects such as 'what we can actually prove', 'what are causal relationships', 'what is knowledge and validation', 'what is their relationship or relative importance when considered along side metaphysics'. He further develops ideas that began (first logically codified) with Locke (or even Bacon) and continued through to Hume, Berkeley etc. He discusses the important notion of the 'sense datum' (along with G.E. Moore, A.J. Ayer, etc.).
Note: 'The Problems of Philosophy' is only a little book but you are rather unlikely to digest it in just one sitting!
I'd strongly recommend both Principia Ethica and The Problems of Philosophy to those studying Quantum Physics, as they deal with what is real and what we know about real things—and things that are seemingly ephemeral but are in fact real (e.g.: zero point energy, virtual particles, potentials). Grasping Russell's solid logic also gives us the mindset to tackle the 'awkward' practice—the philosophically worrying 'logic'—of renormalization and perturbation theory (Yang-Mills etc.) in Quantum Field Theory/QFT and its sibling Quantum Electrodynamics/QED.
Here are the remaining texts. The tally is now 28, I forgot to include several that are important, there's also several 'afterthoughts'.
19. Psychopathology of everyday life—Sigmund Freud. This text may seem a strange inclusion but some of Freud's writings are considered philosophical works. Here, I refer you only to Chapter 1 titled The forgetting of Proper Names. It's only a dozen or so pages so it's a quick read. Whether Freud's analyses is correct or wrong, or that modern science has superseded his work is immaterial here. It's importance to philosophers is that it vividly conveys how a great mind broaches a subject and tackles the analysis and comes to conclusions (it's a rare and insightful opportunity to see a philosopher's mind at work). If you are keen also read Chapter II about the Forgetting of Foreign Words.
20, 21, 22. The Logic of Scientific Discovery | The Open Society and Its Enemies, Vol-I Plato | The Open Society and Its Enemies, Vol-II Hegel & Marx — Karl Popper These books represent only a fraction of Popper's output, albeit influential ones. Popper was a highly influential 20th C. philosopher and his fields are many and diverse—from biology, to the scientific method, to the structure of society, to exploring the subject of knowledge—critical rationalism, etc. If you're already studying HPS then it's likely The Logic of Scientific Discovery is one of your curriculum texts. It's here that Popper argues the notion that made him so widely known in the scientific world—that is, scientific methodology should be based on falsifiability, as experiments cannot prove a theory no matter how many times they're repeated but reproducible experiments can refute or disprove a theory.
The Open Society and Its Enemies is a two volume set. For the moment limit yourself to Vol. I (Vol. II is mentioned to avoid confusion). Like the Austrian School of libertarian economists (Ludwig von Mises, Friedrich Hayek), Popper was heavily influenced by his experience of totalitarianism—communist and fascist regimes before and during WWII, thus his antiauthoritarian views. He argues in favor of the free market, free trade, egalitarianism and liberalism and libertarianism thought. In Volume I he aims criticism at the Platonic concept of the benevolent philosopher king who rules through wisdom and experience. Popper views such rule as totalitarianism even if the dictator/despot is benevolent and wise. He argues that a tolerant society must be tolerant of intolerance—if not, then it too is intolerant. That said, matters aren't quite that simple, he then leads us to the paradox of tolerance, which states that if a society sets no limit on its tolerance then eventually the intolerant will destroy it.
Given current politics where both sides of the political divide are becoming more belligerent and intolerant of each other by the moment, Popper's views in The Open Society and Its Enemies are both strongly argued and very prescient in our troubled times.
(Note: in my comments on The Republic, my suggestion was that one should only confine oneself to Book I. This was for good reason; as later in Book IV Plato develops the notions of society's guardians and philosopher king and this isn't relevant to the matter of formal argument. What's notable here about Book IV popping up here is that a common characteristic of philosophical thought and argument is that new works builds heavily upon past thought. Thus, understanding older philosophical arguments is so important; it's why we still consider Greek philosophy a crucial starting point. Moreover, it illustrates the why one should progress through a formally structured curriculum. As with any study, to stay on course and to progress quickly certain topics are essential prerequisites.
23. Being and Nothingness—Jean-Paul Sartre* This text is one of the pillars of 20th C. existentialism, it's considered a true tour de force in the subject. It deals with one's role in the world—of being an existential human being and everything that implies. I haven't time to delve further here as I'd need to illustrate with longwinded examples. However, I'd suggest one should learn the essential basics of existentialism given that its philosophy is so ingrained in 20th Century thinking. The text's likely too long for an introductory course, so one could consult a précised synopsis (reckon it'd still be considered a 'legitimate' learning exercise (I can hear my once lecturers wincing and grinding teeth at the thought!).
24. No Exit - (Fr. Huis clos)—Jean-Paul Sartre The French title translates into English as 'In Camera' although it's better known as No Exit in the Anglophone world. No Exit is a famed but short [hence quickly read] play by Sartre with an existential undercurrent. It's an overstatement to say the play has a plot, rather it describes a situational existential existence more akin to, say, an extreme version of Samuel Beckett's Waiting for Godot. The play's importance to philosophy is that it examines the human condition—of existence—from the most extreme existential perspective possible. The play depicts a state of hell for those involved. Imagine yourself trapped forever in a room with people you hate or with whom you disagree but with never any possibility of escape. It's an extremely thought-provoking work.
25. Formal/Symbolic Logic Texts I can't provide a list and do justice to it. There are too many and I'm not conversant with the latest ones. However, you must study Formal Logic as, at minimum, it's necessary rigor for one to develop logical thinking (there are also many other reasons). It teaches one to accurately comprehend thus determine the meaning of what is written within texts. Often one's comprehension of written text is superficial and imprecise thus one's perceived or interpreted understanding of it is either a poor chimera of the original or perhaps altogether wrong.
Formal logic provides one with tools—symbolic terminology, methodologies and mathematical logic to analyse statements and propositions then reduce them into logical arguments. Sentences are broken down and atomized into subjects, predicates etc. using true/false truth tables along with other formal procedures. Advanced techniques lead to a detailed Semantic theory of truth as formulated by a long line of logicians from George Boole, to Russell, to Wittgenstein through to Alfred Tarski and others. Formal/symbolic logic is a major and necessary extension to Boolean logic, here's a glimpse: https://en.wikipedia.org/wiki/List_of_logic_symbols
(Note: Logic, in its various forms, is a sub branch of mathematical philosophy of which of itself is an enormously broad subject from before the Ancient Greeks onward to modern mathematical thought of Russell, Wittgenstein, Kurt Gödel (his incompleteness theorem) and numerous others. It's likely this topic is covered in your HPS curriculum, thus it's a redundant exercise for me to do so. In addition, I'm not a mathematician by trade, hence if I offered further advice I'd be doing the subject an injustice.
26. Stanford Encyclopedia of Philosophy: https://plato.stanford.edu/index.html Stanford Encyclopedia of Philosophy is, I'd reckon, the most comprehensive philosophy resource on the web. It covers almost every phil. topic imaginable from ancient Greece to HPS and everything else. Its breath of knowledge intimidates me, in fact almost everyone. Don't let that stop you using it as a primary reference source.
Here are some important mainstream topics not covered in my list that you'll eventually encounter (IMHO, they aren't necessary HPS prerequisites): Geek Epicureanism/epicurean philosophy, Epictetus and other Greek philosophers, Thomas Aquinas, Friedrich Nietzsche, Mary Wollstonecraft, Baruch Spinoza, Georg W.F. Hegel, Karl Marx and 20th Century philosophers including, Martin Heidegger, Jacques Derrida, Michel Foucault, John Rawls, John Ralston Saul and others. (Surely, I've missed some key names but there's plenty here to start with.)
An afterthought, perhaps I should have included these two texts:
27. Tractatus Logico-Philosophicus (aka TLP & Treatise on Logic and Philosophy) — Ludwig Wittgenstein In TLP, Wittgenstein concerns himself with the 'relationships' between logistics of language and reality, how this 'understanding' defines the scope or limits of science. This book has had considerable influence on 20th Century philosophers (Russell, G.E Moore and many others). Note: understanding language semantics and how it plays a role in philosophical thinking, perception and logic is a major aspect of 20th C. philosophy.
28. Language, Truth, and Logic — A.J Ayer I initially omitted this book, as later Ayer was critical of it stating that it contains mistakes of his youth. On second thoughts, I've included it, as the way Ayer explains language, the logic of language structures—propositions, statements (such as tautologies being necessarily true and thus don't need verification), etc. had a defining influence on me (in that they sunk into my grey matter first time). However, I acknowledge this is not sound logic (my only defense is that it was an easy text to digest).
What worries me about HPS is that it shouldn't be studied just on its own, as I see it traditional philosophy ought to be a prerequisite or studied concurrently. As you'll note, this list doesn't include those texts.
Traditional philosophy puts the ethical and logical thinking structures (reasoning processes) in place - it supplies the framework to make HPS more understandable and cohesive.
(In my opinion, both subjects are increasingly important in the modern world as developments in science, engineering and technology generally have reached such a stage of development that we cannot afford for too much to go wrong - the consequences are too great. Both phil. and HPS put things into perspective and thus can have a stabilizing influence - that is if we take them seriously and apply them properly.)