Answering the question, ‘Who is a rational agent?’ is of utmost importance for all moral theories which conceive of the rational agent as their basic moral unit (I call these theories ‘the rational theories of morality’). Surprisingly enough, these theories do not pay much attention to this question, and assume, without offering detailed discussions, certain characterizations of the rational agent. In this paper, I examine what kind of attribute ‘rational’ is. In light of this examination I claim that the rational moral theories are based on a mistaken characterization of the rational agent.

From the pre-Socratics to the present, one primary aim of philosophy has been to learn from arguments. Philosophers have debated whether we could indeed do this, but they have by and large agreed on how we would use arguments if learning from argument was at all possible. They have agreed that we could learn from arguments either by starting with true premises and validly deducing further statements which must also be true and therefore constitute new knowledge, or that we could start from putative premises and validly deduce false consequences thereby showing that our premises were false. Our aim in this paper is to suggest a third alternative: we can learn from plausible arguments (invalid arguments which meet some other unspecified desiderata of approximation to valid arguments) through criticism of such arguments which enable us to discover new problems.

It is in the scholium of the Principia on time, space, place and motion that Newton delivers what is — arguably — a reluctant kiss of betrayal to empiricism. Right there, ‘in the main body of his chief work,’ as E.A. Burtt observes, the deed is done: ‘When we come to Newton's remarks on space and time … he takes personal leave of his empiricism.’ Reichenbach registers the event less charitably, dismissing the ‘crude reification of space that Newton shares with the epistemologically unschooled mind in its naive craving for realism.’ Injury is then added to insult as Reichenbach holds Newtonian mechanics to task for arresting the analysis of the problems of space and time for more than two centuries.