- stimulus
- stimulus, stimulant, excitant, incitement, impetus can all mean an agent that arouses a person or a lower organism or a particualr organ or tissue to activity. Only the first three words have definite and common technical use.Stimulus, in this use chiefly a physiological or psychological term, applies basically to something (as a change in temperature, light, sound, or pressure) that occurs in the internal or external environment of an organism, is perceived by sense organs, and if sufficiently intense induces a neural or equivalent (as tropistic) response{
any physical energy that acts upon a receptor of a living organism. A stimulus causes a reaction in an organism, but not necessarily a response (a reaction of a muscle or gland)— Charles Morris
}{so long as a system recognizes stimuli, and reacts to them with fitting responses, it exercises control. And it may then remain intact and functioning, despite stresses which would otherwise upset its internal coordination— Weisz
}Stimulant, typically a medical term, applies chiefly to a chemical substance and especially to a medicament that does or is intended to vitalize bodily activity, either generally or in respect to a particular system or organ or function{tea, coffee, and cocoa are true stimulants to the heart, nervous system, and kidneys; coffee is more stimulating to the brain, cocoa to the kidneys, while tea occupies a happy position between the two, being mildly stimulating to most of our bodily functions— Ukers
}{drugs which speed up cell activity are called stimulants— Clemensen et ai
}{alcohol produces a false sense of well-being and efficiency, but actually it is a depressant rather than a stimulant—T. L. Engle
}Excitant can come very close to stimulant in some of its uses; thus, one may speak of a substance as a stimulant or an excitant of intestinal motility. But distinctively excitant can apply to either a sought or an unwanted reaction and it can imply, as stimulus often but stimulant rarely does, either the initiating or the vitalizing of a process or activity{these amines, being excitants of the central nervous system, increase intellectual and motor activity, produce insomnia, nervousness, and tremors and have the property of antagonizing mild drug depression— Thienes
}{a great many allergists believed that pine pollen contained little or no excitant of allergy. That is to say, the element within the pollen which stimulates antibody production was absent in pine pollen— Swartz
}In their more general use these three terms are seldom as clearly differentiate as in their basic use. Stimulus and stimulant are usually interchangeably applicable to whatever exerts an impelling or invigorating effect (as on a process, an activity, or a mind){whenever an idea loses its immediate felt quality, it ceases to be an idea and becomes, like an algebraic symbol, a mere stimulus to execute an operation without the need of thinking— Dewey
}{to borrow from commercial banks increases the money supply and is a business stimulant—F. M. Knight
}{the colonial-development money is the extra stimulus to generate development faster than would otherwise be possible— Lewis
}but excitant, here too, is more likely to suggest an initiating{we hold that ethical statements are expressions and excitants of feeling which do not necessarily involve any assertions— Ayer
}and it is applicable when unwanted or undesirable ends result{the desire to gain vast and lucrative readership and audiences is the major excitant to the excesses of which so many are SLware— Newsweek
}Incitement applies to something that moves or impels usually a course of action ; the term tends to emphasize an urging or pressing intended to drive one into moving or acting quickly rather than the result attained{to issue a solemn public condemnation and warning that this attack against the Jewish people is an incitement to massacre— The Nation
}{energies slumbering in him which the incitements of the day do not call forth— James
}{nor could all the incitements of its master induce the beast again to move forward— Galsworthy
}Impetus (see also SPEED 2) usually stresses the stimulation of an increase in the momentum of activity already initiated{what also gave an unusual impetus to the mind of men at this period was the discovery of the New World— Hazlitt
}{in estimating the social importance of this movement, we must be careful to discount the temporary . . . impetus it received from the economic slump of this period— Day Lewis
}But the term sometimes applies also to a stimulus that initiates action{it is the impetus that I ask of you: the will to try— Quiller-Couch
}
New Dictionary of Synonyms. 2014.
