Reality, it cannot be repeated too often, varies with every one of us.

variety is life; uniformity is death

Diversity is life; uniformity is death.

Human variability is immense. We see and hear in varying degrees, our limbs are of different lengths and strengths, our minds process information differently, we communicate using different methods and speeds, we move from place to place via diverse methods, and our eye colors are not the same. Some of us can soothe children, some have spiritual insight, and some discern the emotions of others with astounding skill. Which bodily and mental variabilities are considered inconsequential, which are charming, and which are stigmatized, changes over time-and that is the history of disability.

we know that with cats and dogs and horses and kids, humans, every face is really different. But it’s true with all forms of life.

Variation is clearly nature's way.

In Darwin's time no serious attempt had been made to examine the manifestations of variability. A vast assemblage of miscellaneous facts could formerly be adduced as seemingly comparable illustrations of the phenomenon "Variation." Time has shown this mass of evidence to be capable of analysis. When first promulgated it produced the impression that variability was a phenomenon generally distributed amongst living things in such a way that the specific divisions must be arbitrary. When this variability is sorted out, and is seen to be in part a result of hybridisation, in part a consequence of the persistence of hybrids by parthenogenetic reproduction, a polymorphism due to the continued presence of individuals representing various combinations of Mendelian allelomorphs, partly also the transient effect of alteration in external circumstances, we see how cautious we must be in drawing inferences as to the indefiniteness of specific limits from a bare knowledge that intermediates exist.

It is a law of nature we overlook, that intellectual versatility is the compensation for change, danger and trouble.... Nature never appeals to intelligence until habit and instinct are useless. There is no intelligence where there is no change and no need of change.

Tout ce qui est naturel est varié.

But all evolutionary biologists know that variation itself is nature's only irreducible essence. Variation is the hard reality, not a set of imperfect measures for a central tendency. Means and medians are the abstractions.

It is a law of nature we overlook, that intellectual versatility is the compensation for change, danger, and trouble. An animal perfectly in harmony with its environment is a perfect mechanism. Nature never appeals to intelligence until habit and instinct are useless. There is no intelligence where there is no change and no need of change. Only those animals partake of intelligence that have a huge variety of needs and dangers.

The principles of pleasure are not firm and stable. They are different in all mankind, and variable in every particular with such a diversity that there is no man more different from another than from himself at different times.

...each living creature is said to be alive and to be the same individual — as for example someone is said to be the same person from when he is a child until he comes to be an old man. And yet, if he's called the same, that's despite the fact that he's never made up from the same things, but is always being renewed, and losing what he had before, whether it's hair, or flesh, or bones, or blood, in fact the whole body. And don't suppose that this is just true in the case of the body; in the case of the soul, too, its traits, habits, opinions, desires, pleasures, pains, fears — none of these things is ever the same in any individual, but some are coming into existence, others passing away.

[A]lthough species may be discrete, they have no immutable essence. Variation is the raw material of evolutionary change. It represents the fundamental reality of nature, not an accident about a created norm. Variation is primary; essences are illusory. Species must be defined as ranges of irreducible variation.