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

'The following experiments on Human Faculty are worth recording; they have not been published before. In the days of my youth I felt, at one time, a passionate desire to subjugate the body by the spirit, and among other disciplines determining that my will should replace automatism by hastening or retarding automatic acts. Every breath was submitted to this process with result that the normal power of breathing was dangerously interfered with. It seemed as though I should suffocate if I ceased to will. I had a terrible half-hour; at length, by slow and irregular steps the lost power returned...

'A later experiment was to gain some idea of the commoner feelings in insanity. The method tried was to invest everything I met, whether human, animate or inanimate, with the imaginary attributes of a spy. Having arranged plans, I started on the morning’s walk from Rutland Gate, and found the experiment all too successful. By the time I had walked one and a half miles, and reached the cabstand in Piccadilly at the east end of the Green Park, every horse on the stand seemed to be watching me, either with pricked ears or disguising its espionage. Hours passed before this uncanny sensation wore off, and I feel that I could only too easily reestablish it.

'The third and last experiment of which I will speak was to gain an insight into the abject feelings of barbarians and others concerning the power of images which they know to be of human handiwork. I had visited a large collection of idols gathered by missionaries from many lands, and wondered how each of those absurd and ill-made monstrosities could have obtained the hold over the imaginations of its worshippers. I wished if possible, to enter into those feelings. It was difficult to find a suitable object for trial, because it ought to be in itself quite unfitted to arouse devout feelings. I fixed on a comic picture, it was that of Punch, and made believe in its possession of divine attributes. I addressed it with much quasi-reverence as possessing a mighty power to reward or punish the behaviour of men towards it, and found little difficulty in ignoring the possibilities of what I professed. The experiment gradually succeeded; I began to feel and long retained for the picutre a large share of the feelings that a barbarian entertains towards his idol, and learned to appreciate the enormous potency they might have over him.'

- from Memories of my Life by Francis Galton, 1908

Three great Wikipedia pages I found today:

http://en.wikipedia.org/wiki/Fictitious_entry: "The salesman is put on trial for treason, but reveals that the encyclopedia article for the star system... is a fictitious entry included in the encyclopedia to detect plagiarism..."
http://en.wikipedia.org/wiki/Bielefeld_Conspiracy: "the [Bielefeld] city council released a press statement titled Bielefeld gibt es doch! (Bielefeld does exist!)..."
http://en.wikipedia.org/wiki/Clinamen