All systems need to possess a range of responses to imposed stresses in order to be able to continue to function. A church must be able to withstand the assaults of sociological forces and violent tremblings of the earth. When an archer draws a bow, it must be able to flex sufficiently to accommodate the full length of an arrow. Exceed that level of stress and the bow may be destroyed. An electrical wrist timepiece may function satisfactorily under water to a depth of several meters, but leak and fail when the depth is doubled. A plant species that has evolved the ability to cope with irregular rainfall will be unable to survive when weather patterns change and virtually all precipitation ceases. At an individual level, humans can withstand varying levels of drug intake... depending upon the circumstances their bodily systems are subjected to... but succumb to overdosing or total deprivation. At both an individual and social level, humans will not react adversely to a range of cultural and intellectual behaviours... that do not perturb their established norms of what is acceptable... but engage in violent retribution when these are violated. Tolerance is a blanket evaluation of the ability of a system to resist perturbations.

Exceeding the tolerance of a system is eventually terminal. If a perturbation of a system is not fatal to it, then the system can be thought of as tolerating that level of disturbance. The point at which a system fails indicates the level of disturbance beyond which it is intolerant. If a system cannot be modified or relocated or protected from increasing levels of disturbance, then it will inevitably exceed that which it can tolerate and will fail. An aircraft performing aerobatic manoeuvres that exceed its design tolerances will in all likelihood structurally fail. A species subject to environmental changes that are more rapid than its capacity to evolve compensating adaptations, will become extinct. A dwelling of dry unreinforced quarried stone cannot tolerate the extreme disruptions of a nearby magnitude nine earthquake. On the other hand, strategies are sometimes available or can be devised to avoid exceeding tolerance levels. More powerful drugs can become available to increase resistance levels to pain or infections. Irrigation systems can alleviate the stress levels of water deprivation on crop systems... and so on. The tolerance level of every system can be modified by a variety of strategies, but eventually, every system can be stressed beyond recovery.

At an individual level, tolerance of social ideas and behaviours is a matter of established belief structures and the power of social regulations. If one individual is able to condone the behaviour of another individual without any sort of reaction towards or attempt to prevent that behaviour, then such acceptance can be deemed as tolerance. Intolerance is in evidence by one individual or group when they attempt to suppress or persecute the behaviour of another individual or group. Neither tolerance nor intolerance are intrinsically to be aspired towards or rejected... even though this is often the case. Every society... whether tacitly or by means of legislation... has a range of behaviours which it will tolerate, and a range which it will not. Anthropological studies have revealed innumerable examples... both historical and extant... that would illustrate the reality that the behaviour tolerated by humans is very culturally dependant. Each society is a system wherein reaction and repression occurs when the tolerance level is exceeded. Broadly speaking, a society will not tolerate those ideas or actions that are perceived as being detrimental to that society. Dictatorships will not tolerate dissent... bees will not tolerate being plundered... intelligence organizations will not tolerate spies.....etc The most powerful factions of any society will not tolerate those behaviours that threaten their superiority and control. For the continuing evolution of the power of social cooperation, the only sustainable justifications for the boundaries of what is tolerated and what is not needs to be pragmatically democratic. Religious groups, gangs, political groups, football cubs, ethnic groups, and so on... that are intolerant of other persuasions are undemocratic and hence must have their behaviour 'neutralized' by whatever means it is found necessary to implement. There is no point in being tolerant towards those who are intolerant of the very society they belong to, unless the society in question is sufficiently vigorous and dominant that they can afford the luxury of accepting a low level of dissent. Once the level of intolerant dissent reaches a critical mass however, the very survival of the society comes into question. Civil war is the possible outcome if this phase is entered into. At a societal level tolerance of social ideas and behaviours should be a matter of pragmatic democracy.

Because it is a practical existential impossibility to be universally 'intolerant' of everything and anything, any attempt at proclaiming a philosophical or political perspective that promotes a generalized 'intolerance of intolerance' is a linguistic nonsense. There must always be sensible specific pragmatic limits set to what a society deems to be justifiable tolerance and/or intolerance. A society that expresses a specific intent to be legally intolerant of religious intolerance, or officially tolerant of same-sex marriages is focussing the perspective if its citizens on the import of particular issues, and thereby bypassing the uncertainties and confusion of incomprehensible generalizations.

To repeat the point made in "respect"...
In an attempt to avoid such destructive and self-perpetuating disharmony, so-called 'democratic' societies in particular have attempted to promote the universal acceptance of the idea of 'tolerance and respect' for all. Whilst the initiative is worthy of support... on the grounds of pragmatism, efficiency, and common sense alone... any society that attempts to encourage such an attitude, needs to consider certain factors with great care. 'Tolerance' is not a social characteristic that can be universalized. No society can 'tolerate' everything and anything. In particular, there should be a clearly enunciated range of behaviours that a society will not tolerate... no matter what are the beliefs of its members. If a society decides that it will not tolerate murder, fraud, sexual mutilation, the killing of rhinoceros, the wearing of the niqab, etc... then no-one can be exempt. Certainly NOT for 'religious' reasons. Respect on the other hand must be earned, and the values promoted in evaluating that respect are more likely to result in an integrated and cooperative society if they are egalitarian, pragmatic, altruistic and ecological.