He was born in London in 1871, the eldest child of Walter Stennett Prichard (a solicitor) and his wife Lucy.
He took early retirement from Trinity in 1924 on grounds of ill health, but recovered and was elected White's Professor of Moral Philosophy in 1928 and became a fellow of Corpus Christi College.
[2] Prichard gave an influential defence of ethical intuitionism in his "Does Moral Philosophy Rest on a Mistake?"
The essay laid the groundwork for ethical intuitionism and provided inspiration for some of the most influential moral philosophers, such as John Rawls.
Foundationalism is a theory of epistemology which states that there are certain fundamental principles which are the basis for all other knowledge.
In the case of ethics, foundationalists hold that certain fundamental moral rules are their own justification.
If one begins to doubt one's intuition, one should try to imagine oneself in the moral dilemma related to the decision.
The sense that we ought to do certain things arises in our unreflective consciousness, being an activity of moral thinking occasioned by the various situations in which we find ourselves.
We then want to have it proved to us that we ought to do so, i.e., to be convinced of this by a process which, as an argument, is different in kind from our original and unreflective appreciation of it.
Hence in the first place, if, as is almost universally the case, by Moral Philosophy is meant the knowledge which would satisfy this demand, there is no such knowledge, and all attempts to attain it are doomed to failure because they rest on a mistake, the mistake of supposing the possibility of proving what can only be apprehended directly by an act of moral thinking.