Ronald Fisher

To consult the statistician after an experiment is finished is often merely to ask him to conduct a post mortem examination. He can perhaps say what the experiment died of.

— Ronald Fisher

After all, it is a common weakness of young authors to put too much into their papers.

— Ronald Fisher

… the so-called co-efficient of heritability, which I regard as one of those unfortunate short-cuts, which have often emerged in biometry for lack of a more thorough analysis of the data.

— Ronald Fisher

Natural selection is a mechanism for generating an exceedingly high degree of improbability.

— Ronald Fisher

Faith Is Not Credulity.

— Ronald Fisher

… the best causes tend to attract to their support the worst arguments, which seems to be equally true in the intellectual and in the moral sense.

— Ronald Fisher

More attention to the History of Science is needed, as much by scientists as by historians, and especially by biologists, and this should mean a deliberate attempt to understand the thoughts of the great masters of the past, to see in what circumstances or intellectual milieu their ideas were formed, where they took the wrong turning or stopped short on the right track.

— Ronald Fisher

The million, million, million … to one chance happens once in a million, million, million … times no matter how surprised we may be that it results in us.

— Ronald Fisher

[...] the uncontrolled causes which may influence the result are always strictly innumerable.

— Ronald Fisher

Natural Selection is not evolution.

— Ronald Fisher

No practical biologist interested in sexual reproduction would be led to work out the detailed consequences experienced by organisms having three or more sexes; yet what else should he do if he wishes to understand why the sexes are, in fact, always two?

— Ronald Fisher

No efforts of mine could avail to make the book easy reading.

— Ronald Fisher

We may consequently state the fundamental theorem of Natural Selection in the form : The rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time.

— Ronald Fisher

Professor Eddington has recently remarked that 'The law that entropy always increases — the second law of thermodynamics — holds, I think, the supreme position among the laws of nature'. It is not a little instructive that so similar a law [the fundamental theorem of natural selection] should hold the supreme position among the biological sciences.

— Ronald Fisher

There is, then, in this analysis of variance no indication of any other than innate and heritable factors at work. (Coining of the phrase ‘analysis of variance’.)

— Ronald Fisher

(Coining the phrase ‘test of significance’): Critical tests of this kind may be called tests of significance, and when such tests are available we may discover whether a second sample is or is not significantly different from the first.

— Ronald Fisher

Fairly large print is a real antidote to stiff reading.

— Ronald Fisher

I believe that no one who is familiar, either with mathematical advances in other fields, or with the range of special biological conditions to be considered, would ever conceive that everything could be summed up in a single mathematical formula, however complex.

— Ronald Fisher

However, perhaps the main point is that you are under no obligation to analyse variance into its parts if it does not come apart easily, and its unwillingness to do so naturally indicates that one’s line of approach is not very fruitful.

— Ronald Fisher

The analysis of variance is not a mathematical theorem, but rather a convenient method of arranging the arithmetic.

— Ronald Fisher

(Coining phrase "null hypothesis") In relation to any experiment we may speak of this hypothesis as the “null hypothesis,” and it should be noted that the null hypothesis is never proved or established, but is possibly disproved, in the course of experimentation. Every experiment may be said to exist only in order to give the facts a chance of disproving the null hypothesis.

— Ronald Fisher

Apart from sex linkage, we know almost nothing at present of linkage in man. Yet it is certain that every defect determined by a single factor must be located in one or other of twenty-three [sic] linkage groups. Each defect must therefore be linked in inheritance with numerous other observable traits, and with some of them is probably linked closely. The search for such linkage will certainly be lengthy, and at first, disappointing.

— Ronald Fisher

The academic mind, as we know, is sometimes capable of assuming an aggressive attitude. The official mind, on the contrary, is and has to be, expert in the art of self-defence.

— Ronald Fisher