It appears to me that in Ethics, as in all other philosophical studies, thedifficulties and disagreements, of which its history is full, are mainly due to a very simple cause: namely to the attempt to answer questions, without first discovering precisely what question it is which you desire to answer. I do not know how far this source of error would be done away, if philosophers would try to discover what question they were asking, before they set about to answer it; for the work of analysis and distinction is often very difficult: we may often fail to make the necessary discovery, even though we make a definite attempt to do so. But I am inclined to think that in many cases a resolute attempt would be sufficient to ensure success; so that, if only this attempt were made, many of the most glaring difficulties and disagreements in philosophy would disappear. At all events, philosophers seem, in general, not to make the attempt; and whether in consequence of this omission or not, they are constantly endeavouring to prove that Yes or No will answer questions, to which neither answer is correct, owing to the fact that what they have before their minds is not one question, but several, to some of which the true answer is No, to others Yes.(Preface ¶ 1)

I have tried in this book to distinguish clearly two kinds of question, which moral philosophers have always professed to answer, but which, as I have tried to shew, they have almost always confused both with one another and with other questions. These two questions may be expressed, the first in the form: What kind of things ought to exist for their own sakes? the second in the form: What kind of actions ought we to perform? I have tried to shew exactly what it is that we ask about a thing, when we ask whether it ought to exist for its own sake, is good in itself or has intrinsic value; and exactly what it is that we ask about an action, when we ask whether we ought to do it, whether it is a right action or duty. (Preface ¶ 2)

But from a clear insight into the nature of these two questions, there appears to me to follow a second most important result: namely, what is the nature of the evidence, by which alone any ethical proposition can be proved or disproved, confirmed or rendered doubtful. Once we recognize the exact meaning of the two questions, I think it also becomes plain exactly what kind of reasons are relevant as arguments for or against any particular answer to them. It becomes plain that, for answers to the first question, no relevant evidence whatever can be adduced: from no other truth, except themselves alone, can it be inferred that they are either true or false. We can guard against error only by taking care, that, when we try to answer a question of this kind, we have before our minds that question only, and not some other or others; but that there is great danger of such errors of confusion I have tried to shew, and also what are the chief precautions by the use of which we may guard against them. As for the second question, it becomes equally plain, that any answer to it is capable of proof or disproof—that, indeed, so many different considerations are relevant to its truth or falsehood, as to make the attainment of probability very difficult, and the attainment of certainty impossible. Nevertheless the kind of evidence, which is both necessary and alone relevant to such proof and disproof, is capable of exact definition. Such evidence must contain propositions of two kinds and of two kinds only: it must consist, in the first place, of truths with regard to the results of the action in question—of causal truths—but it must also contain ethical truths of our first or self-evident class. Many truths of both kinds are necessary to the proof that any action ought to be done; and any other kind of evidence is wholly irrelevant. It follows that, if any ethical philosopher offers for propositions of the first kind any evidence whatever, or if, for propositions of the second kind, he either fails to adduce both causal and ethical truths, or adduces truths that are neither, his reasoning has not the least tendency to establish his conclusions. But not only are his conclusions totally devoid of weight: we have, moreover, reason to suspect him of the error of confusion; since the offering of irrelevant evidence generally indicates that the philosopher who offers it has had before his mind, not the question which he professes to answer, but some other entirely different one. Ethical discussion, hitherto, has perhaps consisted chiefly in reasoning of this totally irrelevant kind. (Preface ¶ 3)

One main object of this book may, then, by expressed by slightly changing one of Kant's famous titles. I have endeavoured to write Prolegomena to any future Ethics that can possibly pretend to be scientific. In other words, I have endeavoured to discover what are the fundamental principles of ethical reasoning; and the establishment of these principles, rather than of any conclusions which may be attained by their use, may be regarded as my main object. I have, however, also attempted, in Chapter VI, to present some conclusions, with regard to the proper answer to the question, What is good in itself? which are very different from any which have commonly been advocated by philosophers. I have tried to define the classes within which all great goods and evils fall; and I have maintained that very many different things are good and evil in themselves, and that neither class of things possesses any other proper which is both common to all its members and peculiar to them. (Preface ¶ 4)

In order to express the fact that ethical propositions of my first class are incapable of proof or disproof, I have sometimes followed Sidgwick's usage in calling them Intuitions. But I beg that it may be noticed that I am not an Intuitionist, in the ordinary sense of the term. Sidgwick himself seems never to have been clearly aware of the immense importance of the difference which distinguishes his Intuitionism from the common doctrine, which has generally been called by that name. The Intuitionist proper is distinguished by maintaining that propositions of my second class—propositions which assert that a certain action is right or a duty—are incapable of proof or disproof by any enquiry into the results of such actions. I, on the contrary, am no less anxious to maintain that propositions of this kind are not Intuitions, than to maintain that propositions of my first class are Intuitions. (Preface ¶ 5)

Again, I would wish it observed that, when I call such propositions Intuitions, I mean merely to assert that they are incapable of proof; I imply nothing whatever as to the manner or origin of our cognition of them. Still less do I imply (as most Intuitionists have done) that any proposition whatever is true, because we cognise it in a particular way or by the exercise of any particular faculty: I hold, on the contrary, that in every way in which it is possible to cognise a true proposition, it is also possible to cognise a false one. (Preface ¶ 6)

When this book had been already completed, I found, in Brentano's Origin of the Knowledge of Right and Wrong, opinions far more closely resembling my own, than those of any other ethical writer with whom I am acquainted. Brentano appears to agree with me completely (1) in regarding all ethical propositions as defined by the fact that they predicate a single unique objective concept; (2) in dividing such propositions sharply into the same two kinds; (3) in holding that the first kind are incapable of proof; and (4) with regard to the kind of evidence which is necessary and relevant to the proof of the second kind. But he regards the fundamental ethical concept as being, not the simple one which I denote by good, but the complex one which I have taken to define beautiful; and he does not recognize, but even denies by implication, the principle which I have called the principle of organic unities. In consequence of these two differences, his conclusions as to what things are good in themselves, also differ very materially from mine. He agrees, however, that there are many different goods, and that the love of good and beautiful objects constitutes an important class among them.(Preface ¶ 7)

I wish to refer to one oversight, of which I became aware only when it was too late to correct it, and which may, I am afraid, cause unnecessary trouble to some readers. I have ommitted to discuss directly the mutual relations of the several different notions, which are all expressed by the word end. The consequences of this omission may be partially avoided by a reference to my article on Teleology in Baldwin's Dictionary of Philosophy and Psychology.(Preface ¶ 8)

If I were to rewrite my work now, I should make a very different, and I believe that I could make a much better book. But it may be doubted whether, in attempting to satisfy myself, I might not merely render more obscure the ideas which I am most anxious to convey, without a corresponding gain in completeness and accuracy. However that may be, my belief that to publish the book as it stands was probably the best thing I could do, does not prevent me from being painfully aware that it is full of defects.(Preface ¶ 9)

TRINITY COLLEGE, CAMBRIDGE

August, 1903(Preface ¶ 10)