1. In common use, _necessity_ "is a relative term, and relates to some supposed opposition made to the existence of a thing, which opposition is overcome or proves insufficient to hinder or alter it. The word _impossible_ is manifestly a relative term, and has reference to supposed power exerted to bring a thing to pass which is insufficient for the effect. The word _unable_ is relative, and has relation to ability, or endeavour, which is insufficient. The word _irresistible_ is relative, and has reference to resistance which is made, or may be made, to some force or power tending to an effect, and is insufficient to withstand the power or hinder the effect. The common notion of necessity and impossibility implies _something that frustrates endeavour or desire_." He then distinguishes this necessity into _general and particular_. "Things are necessary _in general_, which are or will be, notwithstanding any supposable opposition, from whatever quarter:" e. g. that God will judge the world. "Things are necessary _to us_ which are or will be, notwithstanding all opposition supposable in the case _from us_." This is _particular_ necessity: e. g. any event which I cannot hinder. In the discussions "about liberty and moral agency," the word is used especially in a particular sense, because we are concerned in these discussions _as individuals_. According to this _common use_ of necessity in the _particular_ sense, "When we speak of any thing necessary _to us_, it is with relation to some supposable opposition _to our wills;_" and "a thing is said to be necessary" in this sense "when we cannot help it, do what _we will_." So also a thing is said to be _impossible to us_ when we cannot do it, although we make the attempt,--that is, put forth the volition; and _irresistible to us_, which, when we put forth a volition to hinder it, overcomes the opposition: and we are _unable_ to do a thing "when our supposable desires and endeavours are insufficient,"--are not followed by any effect. In the common or vulgar use of these terms, we are not considering volition in relation to its own cause; but we are considering volition as itself a cause in relation to its own effects: e. g. suppose a question be raised, whether a certain man can raise a certain weight,--if it be affirmed that it is _impossible_ for him to raise it, that he has not the _ability_ to raise it, and that the weight will _necessarily_ keep its position,--no reference whatever is made to the production of a volition or choice to raise it, but solely to the connexion between the _volition_ and the _raising of the weight_. Now Edwards remarks, that this common use of the term necessity and its cognates being habitual, is likely to enter into and confound our reasonings on subjects where it is inadmissible from the nature of the case. We must therefore be careful to discriminate. (p. 27.)