The writings of Tertullian of North Africa which bear on the nature of the church and of Christian ministry mark an important stage in a development from the fluid ecclesial concepts of the second century to the more fixed structures of the third. This is a shift from a dominant concern for the preservation of authentic apostolic doctrine to one for the validation of a regular, prescribed apostolic office.

Until the end of the second century nowhere is there in Christian thought–neither in the West nor the East–evidence of a clearly defined ecclesiology; that is, no extant Christian document of the period possesses a coherent and comprehensive doctrine of the church. It might be said that prior to the end of the second century the existence and the nature of the church were taken for granted. There is little evidence that any Christian writer before Tertullian had given attention to the question of the church's essential marks or notes. None appears to have gone beyond the reproduction of biblical images such as ‘the body of Christ’ and ‘the bride of Christ’. Yet, by the middle of the third century, in the writings of the most prominent Western churchman of the time, Cyprian of Carthage, a highly developed ecclesiology had emerged. Questions of apostolic orthodoxy and a due order in Christian ministry and office aside, the church simply was. Its raison d'être was its existence. It was, at most, a means to an end, and no end in itself.

Locke, no friend of innate principles, would normally be considered, a fortiori, no friend of Plato. But while there are undeniable and obvious differences between the two philosophers, this chapter is intended to bring out some remarkable affinities between them. To do this we shall be focusing on Locke's attack on moral innatism in the first book of the Essay concerning Human Understanding. After first sketching out the background to this attack, I wish to show that, as we might by now be expecting, when Locke comes to attack moral innatism, he selects something far more like the Stoic theory than the Platonic as his target. Admittedly, he does not simply do this because that was the theory that happened to be around at the time; he himself believes that if there were to be an innatist theory, that would be the most plausible; and he actually supplies arguments of his own to show this. But despite this limited concession to those who espoused the Stoic form of innateness, he then turns against it using arguments that sound strangely Platonic.

BACKGROUND TO ESSAY I iii

Locke starts his attack on innatism in the second chapter of book I and his overall strategy remains clear and systematic throughout: the second chapter deals with speculative maxims, the third with practical (i.e. moral) principles and the fourth with ideas such as those of God and substance. Another way of seeing the division of labour is that the second and third chapters deal with principles or propositions alleged to be innate, whereas the fourth concentrates mostly on ideas.

MINISTRY AS ‘SERVICE’

Tertullian rarely speaks of ministry in the sense of a general ‘service’. There are very few references in his extant writings to any such service in the sense of the Greek ‘diakonia’. When he wants to refer to ministry in such terms, however, he normally employs ‘ministerium’, ‘virtutes’ or ‘charismata’, or even ‘officium’ (though this latter term can also be used of ‘office’ proper).

‘Ministerium’

‘Ministerium’ is an obvious Latin translation for the Greek words ‘diakonia’ – though not to be confused with the formal, diaconal order – ‘leitourgia’ and ‘latreia’. Yet only once, at De Oratione 15,1, does Tertullian directly quote a New Testament passage in which one such ‘service-ministry’ expression is found. Tertullian here translates the Greek ‘latreia’ from Romans 15,1, as ‘officium’ with its alternative and (here) appropriate meaning of a ‘ceremonial observance’.

There are no obvious patristic precedents by which to appreciate better Tertullian's employment of the word ‘ministerium’. He employs it with a wide variety of meanings, though usually with reference to non-ecclesiastical matters. He employs it to mean ‘implements’ at Adv. Marcionem 11,16,2, a ‘fellow culprit’ at De Anima 40,4, an ‘agency (of persecution)’ at De Fuga 2,1, the ‘exousiai’ (rulers) mentioned at Romans 13,1, ‘ministers (of God)’ at Scorpiace 14,1 (again as part of a translation of Romans 13), and the organs of the human body at De Corona 5,2. Tertullian also calls ‘exomologesis’ a ‘ministerium’ (handmaid) of repentance at De Paenitentia 12,8 and refers to the ‘sacrificial services’ of Numa Pompilius as ‘ministeria’ at De Praescriptione 40,6.

Occasional references to an ‘ecclesia in caelis’ can be found in Tertullian's writings. Yet, for the most part, Tertullian sees the true church as an historical, empirical reality the authentication for which can be found at least partly in the present age. This reality is partly determined by the nature and the circumstances of the church's foundation by the apostles, and partly by its Spirit-driven activity in the present time, but, above all, by its present nature, consistent with its promise as the eschatological community, as both the Body of Christ and the Bride of Christ. This church in the power of the Spirit, which power enables it to become now what it is in promise, is not yet the Kingdom of God, but its anticipation in history. In this Tertullian differs from both Origen and Clement of Alexandria, for example, for whom the present reality is but an imperfect shadow of some heavenly, as yet unrealised ideal. Tertullian is consistent in his understanding of the historical and empirical nature of this church, and, in this sense, no significant difference is discernible in his ecclesiology in the transition from Catholic to New Prophet. What do change, however, are the criteria by which for him the reality and the authentication of the true church are evaluated; that is, what it is for this church to be faithful to its essential and authentic nature.

Some of the images employed by Tertullian to depict the church are drawn from secular life, though most do have biblical and other Christian connections.

Although he briefly considers the notion of contingency (or two-way possibility) in chapter 3, Aristotle does not formulate his “official” definition of this modality until chapter 13: “I mean, by being contingent, and by that which is contingent, whatever is not necessary but, being assumed to obtain, entails no impossible consequences” (32a18–20). “Impossible” in the definiens must refer here to “one-way” possibility, defined as “not necessarily not,” with contingency (two-way possibility) defined in terms of necessity and/or one-way possibility.

We shall consider, however, Wieland's claim that two-way possibility is a modality sui generis. And from a larger perspective, one is confronted with difficult issues concerning the relation of contingency to “belonging by nature,” or “applying always or for the most part,” and, in turn, of the importance of Aristotle's logic of two-way possibility (developed in chapters 14–22 of Pr. An. A) for Aristotelian science. Aristotle touches on this last problem without resolving it in A.3 (25b14–31) and again in A.13 (32b4–22), where he asserts that there are scientific demonstrations concerning things associated “by nature or for the most part,” but not concerning chance associations.

Prominent among the more specific issues are, once again, those having to do with conversion. Here we encounter the usual questions about conversion of terms within A, E, I, and O propositions, only now in a way that requires resolution of a related issue about the “quality” (affirmative or negative) of two-way possibility propositions.

In chapters 14–22, Aristotle methodically considers all the various combinations of premise pairs involving at least one two-way possibility (“problematic” or “contingent”) premise. Chapters 14–16 take up firstfigure moods having, respectively, two problematic premises, one problematic and one assertoric premise, and one problematic and one necessity premise. Chapters 17–19 take up the same combinations, now in the second figure, and 20–22 carry the plan through the third figure. (For a chart of the ground plan of chapters 8–11 and 14–22, see the first page of Chapter 3 herein.) As with the necessity syllogisms of 8–11 and the assertoric ones of 4–6, Aristotle singles out the “complete” or “perfect” (teleios) moods, those whose validity is obvious on the basis of the premises precisely as given, and then validates other moods by reducing them to perfect moods by use of term or qualitative conversion or reductio ad impossibile, or by validating them through ekthesis. Some portions of these chapters are fairly routine and so will be presented here in summary fashion. This will leave us free to focus on a number of logical curiosities and on some significant philosophical issues, including that of the relation of these syllogisms to Aristotelian science.

TWO PROBLEMATIC PREMISES: FIRST FIGURE

All the perfect moods with this combination of premises fall into the first figure and correspond exactly to the four perfect plain moods of Pr. An. A.4. Thus, chapter 14 consists in a discussion of Barbara, Celarent, Darii, and Ferio pp, pp/pp, and of several invalid moods.

BACKGROUND TO THE PRINCIPAL ISSUES

The chapters of the Prior Analytics devoted to modal arguments are notoriously difficult, controversial, and, according to numerous weighty authorities, deeply confused. Accordingly, one major aim of this study will be to examine in detail the internal workings of Aristotle's modal logic – his logic not just of statements simply asserting the application of a predicate to a subject but also of those asserting a necessary or possible or contingent relation between subject and predicate – in order to understand and assess its strengths and its weaknesses. A second aim will be to establish a fundamental connection between Aristotle's metaphysical essentialism (along with his theory of scientific demonstration) on the one hand and his modal logic on the other. These two goals are closely connected, or so it will be argued here, in that the logical system itself must be understood from the start in the light of basic points of syntax and semantics deriving from Aristotle's views on what there is and on the various ways in which we can speak and reason about what there is.

There has always been healthy interest in Aristotle's metaphysical essentialism – interest heightened recently by work on essentialism as such, and especially by work deriving, like Aristotelian essentialism, from intuitions about the natures or essences of things. Such developments have contributed at least indirectly to the study of Aristotle by provoking careful thought about how essentialism might be formulated and how different objects (individual living things, the “natural kinds” of chemistry or physics or biology, sets, numbers) might involve very different sorts of essential properties, discoverable only through a variety of approaches.

Aristotle's syllogistic encompasses several groups of syllogisms— the assertoric ones and six or so modal groups (the exact number would be a matter of contention and is not important here). Almost without exception each type (e.g., those with necessary premises and conclusion) contains its own subset of “perfect” or “complete” (teleios) syllogisms, perfect because they are not only valid, but obviously so just as they stand, and another set of imperfect ones whose validity must be demonstrated “by something additional,” usually by reduction to one or another perfect syllogism. Aristotle says relatively little about this perfection, and for the most part the commentators follow him in this. Everyone agrees that he has in mind, at least in part, the psychological feature of obviousness of validity; but some would maintain – and here controversy begins to set in – that for the assertoric case, at least, he also has in mind a single logical principle that is itself obviously valid and that directly entails the perfect syllogisms Barbara, Celarent, Darii, and Ferio. The principle in question is the dictum de omni et nullo: Everything predicated (or not predicated) of all of some group is predicated (not predicated) of everything contained in that group. If Aristotle does have such a principle in mind, the question arises whether he meant it to apply also to perfect modal syllogisms and hence whether he had a single underlying principle that could ground the perfection of all his perfect syllogisms, plain or modal.