Forced Move

Term
 A move that reason mandates an actor make.
Explanation
“We can look back and see that our case of necessity, having an autonomous metabolism, can be recast as simply the only acceptable solution to the most general design problem of life. If you wanna live, you gotta eat. In chess, when there is only one way of staving off disaster, it is called a forced move. Such a move is not forced by the rules of chess, and certainly not by the laws of physics (you can always kick the table over and run away), but by what Hume might call a ‘dictate of reason’. It is simply dead obvious that there is one and only one solution, as anybody with an ounce of wit can plainly see. Any alternatives are immediately suicidal.” (128, Darwin’s Dangerous Idea)
Source
Darwin’s Dangerous Idea by Daniel Dennett

Blind Necessity

Term
When there is a rational necessity to a step occurring despite the chance of that step occurring being random.
This refers mainly to a forced move in evolution, where an organism is forced to select for a particular trait despite the mutation leading to traits being random. Frequently these are circumstances that are contingent in the realms of physics and logical possibility but necessary in the realm of biology.
Explanation
“So at least some ‘biological necessities’ may be recast as obvious solutions to most general problems, as forced moves in Design Space. These are cases in which, for one reason or another, there is only one way things can be done. But reasons can be deep or shallow. The deep reasons are the constraints of the laws of physics — such as the Second Law of Threnodynamics, or the laws of mathematics or logic. The shallow reasons are just historical. There used to be two or more ways this problem might be solved, but now that some historical accident has sent us off down one particular path, only one way is remotely available; it has become a ‘virtual necessity,’ a necessity for all practical purposes, given the cards that have been dealt. The other options are really no longer any other options at all.
     The marriage of chance and necessity is a hallmark of biological regularities. People often want to ask: ‘Is it merely a massively contingent fact that circumstances are as they are, or can we read some deep necessity into them?’ The answer is almost always: Both. But note that the type of necessity that fits so well with the chance of random, blind generation is the necessity of reason. It is an inescapably teleological variety of necessity, the dictate of what Aristotle called practical reasoning” (129, Darwin’s Dangerous Idea)
Source
Darwin’s Dangerous Idea by Daniel Dennett

Sparsensess Principle

Principle
“The Sparseness Principle: When relatively simple processes produce similar things, those things will tend to be identical!” (Communication with Alien Intelligence)
“Whenever two relatively simple processes have products which are similar, those products are likely to be completely identical” (130, Darwin’ Dangerous Idea)
Explanation
“Consider the set of possible processes, which Minsky interprets a lá  the Library of Babel as all permutations of possible computers….Except for a Vanishing few, the Vast majority of these processes ‘do scarcely anything at all.’ So if you find ‘two’ that do something similar (and worth noticing), they are almost to be bound to be one and the same at some level of analysis.” (130, Darwin’s Dangerous Idea)
Source
Darwin’s Dangerous Idea by Daniel Dennett

Homology

Term
When a trait arises due in the course of evolution to copying rather than for purely functional reasons.
Explanation
“The curious fallings short of what would seem to be perfect design, that are the best evidence for a historical process of descent with modification; they are the best evidence of copying, instead of independent re-inventing, of the the design in question. We can now see better why this such good evidence. The odds against two independent processes arriving at the same region of Design Space are Vast unless the design element in question is obviously right, a forced move in Design Space. Perfection will be independently hit upon again and again, especially if it is obvious. It is the idiosyncratic versions of near-perfection that are dead giveaway of copying. In evolutionary theory, such traits are called homologies: traits that are similar not because they have to be for functional reasons, but because of copying.” (136, Darwin’s Dangerous Idea)
Source
Darwin’s Dangerous Idea

The Organism’s Greater Good

Principle
When a group of self-interested individuals has selfish interest in seeing that instances of selfishness get punished. An individual displaying selfish behavior will be punished those whose self-interest is negatively affected by his selfish behavior.
Explanation
“Yet these phenomena are rare. What stops the mutiny? Why do segregation distorters, B chromosomes and cancer cells not succeed in winning the contest? Why does harmony generally prevail over selfishness? Because the organism, the coagulation, asserts its greater interest. But what is the organism? There is no such thing. It is merely the sum of the selfish parts;; and a group of units selected to be selfish cannot surely turn altruistic.
     The resolution of this paradox takes us back to the honey bees. Each worker bee has a selfish inter in producing drones; but each worker equally has a selfish interests that no other worker produce drones. For every self drone-producer there are thousands of bees with a selfish interest in preventing drone production. So a bee hive is not, as Shakespeare thought, a despotism, run from above. It is a democracy, in which the individual wishes of the many prevail over the egoism of each” (33, The Origins of Virtue)
Source
The Origins of Virtue by Matt Ridley

Groupishness

Term
The integrity of the whole being defended by repressing the mutiny of individuals.
Explanation
“The lack of nepotism makes the analogy between people and social insects faulty. Far from embracing vicarious reproduction, we seem to go to great lengths to avoid it. But it does not affect the analogy with chromosomes, which are even more egalitarian about reproduction. Chromosomes may not be altruistic — the do not surrender their right to replicate — but they are something other than selfish. They are ‘groups’: they defend the integrity of the whole genome, suppressing selfish mutinies by individual genes.” (40, The Origins of Virtue)
Source
The Origins of Virtue by Matt Ridley

Division of Labor

Principle
When members of a group specialize at tasks that would be normally be pursued by each individual separately, the aggregate task output of the group specializing at tasks will be greater than the task output of a group that chose not to specialize at tasks.
Explanation
“Somebody not trained in pinking could probably only make one pin a day, and even when practised he would only be able to make twenty or so. Yet, dividing labour between pin-makers and non-pin-makers and by further dividing the task of pin manufacture between a number of specialist trades, we vastly increase the number of pins that can be made by each person. Ten people in a pin factory could and did, said Smith, produce 48,000 pins a day. To buy twenty pins from such a factor therefore costs only 1/240 of a man-day, whereas would have taken a purchaser a whole day at least to make them himself.
     The reasons for this advantage, said Smith, lay in three chief consequences of the division of labour. By specializing in pin-making, the pin-maker improves his dexterity at pin-making through practice; he also saves the time that would otherwise be spent switching from task to task; and it pays him to invent, buy or use specialized machinery that speeds up that task” (42, The Origins of Virtue)
Source
 
The Origins of Virtue by Matt Ridley