Galton as the first existentialist:

'Many years later, I was so harassed with the old question of Determinism, which would leave every human action under the control of Heredity and Environment, that I made a series of observations on the actions of my own mind in relation to Free Will. I emply the word not merely as meaning ‘unhindered’ but in the special sense of an uncaused and creative action. It was carried on almost continuously for six weeks, and off and on for many subsequent months. The procedure was this. Whenever I caught myself in an act of what seemed to be ‘Free Will’, in the above sense, I checked myself and tried hard to recollect what had happened before, made rapid notes and then wrote a full account of the case. To my surprise, I found, after some days’ work, that the occasions were rare in which there seemed room for the exercise of Free Will as defined above. I subsequently reckoned that they did not occur oftener that once a day. Motives for all the other events could be traced backwards in succession, by orderly and continuous steps, until they led into a tangle of familiar paths. It was curous to watch the increase of power, given by practice, of recalling mental actions which, being usually overlooked, give the false idea that much has been performed through a creative act, or by inspiration, which is really due to straightfoward causation... The general result of the inquiry was to support the views of those who hold that man is little more than a concious machine, the slave of heredity and environment, the larger part, perhaps all, of whose actions are therefore predictable.'

- from Memories of my Life by Francis Galton, 1908