In this and the following volumes I wish to publish a selection of the philosophical remarks which I have written down in the course of the last nine years. They concern many topics of philosophical speculation: the concepts of ‘meaning’, ‘understanding’, ‘proposition’, ‘logic’, the foundations of mathematics, sensedata, the conflict between realism and idealism, and others. All these thoughts were originally written down in the form of remarks (short paragraphs) sometimes forming connected series on the same subject, sometimes shifting rapidly from one subject to another. My intention was – some day to bring them all together in a book; regarding the form of this book I had various ideas at different times. It seemed essential however that the thoughts in it should pass from one subject to another in an ordered sequence.

     About four years ago I made the first attempt to collect my remarks in this way. The result was unsatisfactory and I made various further attempts. Until, two years later, I arrived at the conclusion that it was all in vain and I ought to give up any such attempt. It became clear to me that the best I ever could write would just be philosophical remarks; that my thoughts soon grew lame if, against their natural inclination, I forced them along a single track.– This, however, was not unconnected with the nature of the subject itself. This subject compels us to travel through the field of thought in all directions by a host of different routes. And thus the thoughts do not naturally form a simple sequence but a complicated network.

     I begin these publications with the fragment of my last attempt to arrange my philosophical thoughts in an ordered sequence. This fragment has perhaps the advantage of giving comparatively easily an idea of my method. I intend to follow up this fragment with a mass of remarks more or less loosely arranged; and I shall explain the connections between my remarks, where the arrangement does not itself make them apparent, by a system of cross-references thus: each remark shall have a current number and besides this the numbers of those remarks which stand to it in important relations.

     I wish all these remarks were better than they are. They are – to put it shortly – lacking in force and in precision.– I am here publishing those which do not seem to me too dull.

     Until a short time ago I had practically given up the idea of publishing them during my lifetime. But the idea was revived in me, perhaps chiefly, by the fact that I found that the results of my work, which I had passed on in lectures and discussions, were circulating, frequently misunderstood, more or less watered down or mutilated. By this my vanity was stung and it threatened to pester me again and again if I did not settle the matter, at least for myself, by publishing. And this seemed the most desirable thing from other points of view as well.

     For various reasons what I publish here will coincide with what others are writing to-day. If my remarks do not bear a stamp which marks them as mine, – I will lay no further claim to them.

     Since, about ten years ago, I again started to work at philosophy I have had to recognise grave mistakes in what I once set down in my book “Tractatus Logico-philosophicus”. What helped me to recognise these mistakes was – in a measure which I can hardly now estimate – the forceful criticism which my ideas received from F.P. Ramsey; with whom I went over them in innumerable discussions during the last two years of his life.– Even more, however, I owe to the criticism which Mr P. Sraffa, Lecturer in Economics at this University, has incessantly offered on my views. To this stimulus I owe the most fruitful of the thoughts I here communicate.

I publish them not without misgivings. I don't dare to hope that it should fall to the lot of this inadequate work to throw light into this or that brain, in our dark age.

     I don't by my writing wish to save others the trouble of thinking; but rather, if it were possible, to stimulate someone to thoughts of his own.