A philosophical should include everything that can be conceived. In science it need not be comprehensive, physics as a science does not include the study of everything, it excludes the study of life that is the studied by biology. Physics deals only with matter, biology deals with life, so physics need not be comprehensive, biology need not be comprehensive but philosophy is comprehensive, it includes everything.
Whatever statement you make ultimately in philosophy, it should be a vast comprehensive statement, as large as ‘The Life Divine’ the whole book. If you have seen the book, ‘The Life Divine’, one thousand pages and more, it's a long statement and a large statement of one thousand pages. It's a great book of philosophy because it is consistent and comprehensive; it deals with all that exists, all that is conceivable, all that is conceived. It contains also that which is not conceivable but which is conceived to be inconceivable. So, all concepts and concepts of that even of that which is not conceivable, such a large statement that is the speciality of philosophy, it is consistent and comprehensive.
Remark: I don't understand concepts that cannot be conceived?
Answer: Good, I deliberately used that word, so that it may not be conceived. Conception of that which is not conceivable, conception of, not what is not conceived; there is a difference between concept of the unconceived and the concept of the inconceivable. Have you conceived of a horse with wings?
Comment: By imagination?
Answer: So, you can say the horse with wings ordinarily I do not conceive but in imagination, I can conceive. You have the conception of it. Now, if I ask you the question, can you conceive of a unicorn, once again you can conceive, you've not seen, you've not experienced but you can say that it can be conceived. Do you ever use the expression that I have no conception of it at all, I have no idea, have you used any such expression in your life?
In philosophy the question is, you should be able to conceive at the highest level, conceivable is conceivable at the highest possible level, if you can't conceive at this level but if you can conceive at a higher level it becomes conceivable. The mark of philosophical thinking is that that you've striven hardest to arrive at conception even that which you cannot normally conceive, you strive to conceive it. If you fail then you say it is inconceivable, you try your hardest to conceive, having done your hardest and you still cannot conceive then you say it is not conceivable.
Remark: If I can't conceive that does not mean it is inconceivable,
Answer: You're right; therefore, you should go to the wisest. In philosophy, if you say, ‘well! I don't accept it's not enough.’ You should say I have gone round the whole world, knocked every door and asked this question that's the mark of a philosopher.
A philosopher is one who has been trying to conceive the highest, the best and most comprehensive, whatever is the most comprehensive; you should be able to strive at it and yet you arrive at some things which are not conceivable. Take for example, there is a concept now in modern physics, there are two words in modern physics which are very important, ‘particle’ and ‘wave’,− particle is conceivable, wave is conceivable. I ask you the question, give me your understanding of the word ‘particle’, what is it?
Good, now compare it with the idea of a wave. What is the wave, lot of dots in a special manner, right? A wave should really be a wave; not only so many dots put together; it should be wavy in character. Now, a dot, or a particle is conceivable, a wave is conceivable but if I say: particle is the same as wave; try to conceive it. The particle is the same as a wave, particle which is a dot is also the wave.