Let us leave the paltry statements of theologians and note how men who investigate questions more thoroughly have dealt with Morality. Descartes defines Morality as the sustained endeavour to do that which one has recognized to be right. It is difficult to discern in this definition the father of scientific scepticism. What are the distinguishing marks of Right? Is the decision as to what is right and what is wrong to be left to the subjective judgment of the individual? In that case Descartes must concede that the action of a burglar is moral, if he has recognized that it is right for him to perpetrate his crime between two and three o'clock in the morning, that being the most favourable time for it, and then strives to the best of his ability to effect an entrance into the building he has selected, at the moment which he has recognized as the right one. Or shall all mankind, or at least the majority, and not the individual, decide what is right? In that case the definition would certainly approximate to the one which I hold to be true; but for one thing it would suffer from vagueness; and, moreover, its originator would lay himself open to the reproach of not having shown why the individual is worthy of praise when he acts in accordance with the convictions of the majority, though these be opposed to his own, and in so doing allows his action to be determined by a judgment due to a psychic mechanism other than his.
Spinoza's "Ethics" leaves the reader in great discomfort, the result of vacillating and contradictory explanations. Obviously Descartes' great disciple had no clear conception of the essence of Morality and held either consecutively, or may be even simultaneously, divers views on the subject, amongst which those of all schools of thought are either quite clearly expressed or at least implied. "By Good," he says, "I mean that which we know for certain to be useful to us."[1]
[1] I quote the wording of Berthold Auerbach's translation: "B. de Spinoza's collected works. Translated from the Latin by Berthold Auerbach." Stuttgart, J. G. Cotta, 1871. Second edition, Vol. II.
And again: "To act absolutely virtuously is merely to act, live, preserve one's being (these three mean the same thing) in accordance with the dictates of Reason, because one seeks one's own interest."