“It is usually said (and I used to say) that smoking facilitates mental work. And that is undoubtedly true if one considers only the quantity of one’s mental output. To a man who smokes, and who consequently ceases strictly to appraise and weigh his thoughts, it seems as if he suddenly had many thoughts. But this is not because he really has many thoughts, but only because he has lost control of his thoughts.
When a man works he is always conscious of two beings in himself: the one works, the other appraises the work. The stricter the appraisement the slower and the better is the work; and vice versa, when the appraiser is under the influence of something that stupefies him, more work gets done, but its quality is poorer.
‘If I do not smoke I cannot write. I cannot get on; I begin and cannot continue,’ is what is usually said, and what I used to say. What does it really mean? It means either that you have nothing to write, or that what you wish to write has not yet matured in your consciousness but is only beginning dimly to present itself to you, and the appraising critic within, when not stupefied with tobacco, tells you so. If you did not smoke, you would either abandon what you have begun, or you would wait until your thought has cleared itself in your mind; you would try to penetrate into what presents itself dimly to you, would consider the objections that offer themselves, and would turn all your attention to the elucidation of the thought.
But you smoke, the critic within you is stupefied, and the hindrance to your work is removed. What seemed insignificant to you when not inebriated by tobacco, again seems important; what seemed obscure no longer seems so; the objections that presented themselves vanish and you continue to write, and write much and rapidly.
…
It is very probable, as a friend remarked to me, that Kant‘s works would not have been written in such a curious and bad style had he not smoked so much.”
–Leo Tolstoy “Why Do Men Stupefy Themselves” 1890