My introduction to philosophy was Bertrand Russell’s History of Western Philosophy, which I read while in high school (there were no philosophy classes in Australian high schools then) so that clearly had a significant influence on me, but more in informing me about what philosophy is, and in interesting me in some of the ideas discussed, rather than in the sense of influencing me in specific beliefs. Sidgwick’s The Methods of Ethics had a much greater influence on me, firstly in showing me how many commonsense moral rules can be explained as offering a morality that is easier for people to follow, in everyday life, than utilitarianism, but will generally lead to the kind of outcomes that utilitarians favor. R.M. Hare’s work was also influential, in the same direction—here I have in mind Freedom and Reason, and his later work, Moral Thinking. Jonathan Glover’s Causing Death and Saving Lives illustrated the importance of clear thinking for handling life and death questions in bioethics, and led me in that direction. Finally, Derek Parfit has had a major influence on me, initially through his teaching at Oxford, where I first came across the issues in population ethics that he later discussed in Reasons and Persons, and then later through On What Matters, which, as discussed in the interview mentioned in another comment above, persuaded me that Hume was wrong about reason being the slave of the passions, and led me to hold that there are objective truths in ethics.
My introduction to philosophy was Bertrand Russell’s History of Western Philosophy, which I read while in high school (there were no philosophy classes in Australian high schools then) so that clearly had a significant influence on me, but more in informing me about what philosophy is, and in interesting me in some of the ideas discussed, rather than in the sense of influencing me in specific beliefs. Sidgwick’s The Methods of Ethics had a much greater influence on me, firstly in showing me how many commonsense moral rules can be explained as offering a morality that is easier for people to follow, in everyday life, than utilitarianism, but will generally lead to the kind of outcomes that utilitarians favor. R.M. Hare’s work was also influential, in the same direction—here I have in mind Freedom and Reason, and his later work, Moral Thinking. Jonathan Glover’s Causing Death and Saving Lives illustrated the importance of clear thinking for handling life and death questions in bioethics, and led me in that direction. Finally, Derek Parfit has had a major influence on me, initially through his teaching at Oxford, where I first came across the issues in population ethics that he later discussed in Reasons and Persons, and then later through On What Matters, which, as discussed in the interview mentioned in another comment above, persuaded me that Hume was wrong about reason being the slave of the passions, and led me to hold that there are objective truths in ethics.