When blogging about Wolff's German metaphysics, I described his idea of modalities through an analogy of an ocean warmed by sun: possibilities swam like drops of water within the ocean, and occasionally heat of the sun made one such drop rise to the air of actuality. In this text I am going to dive deeper to that ocean and describe in more detail its denizens or possibilities. But before going into possibilities, I must begin with impossibilities.
As should be familiar, Wolff defines impossibility through the notion of contradiction: what is contradictory cannot exist and vice versa. Impossibility is then also identified with what in previous text was called nothing. Possibility is defined as contradictory of impossibility, that is, possibility is something or what is not contradictory.
Now the definition above gives a rather good recipe for recognizing an impossibility – if a contradiction pops up, it cannot be. On the contrary, it is still uncertain how one can recognize something as possible, because it is more difficult to know when something is without contradiction. Wolff himself mentions that we can have a priori proofs that something is possible, which might sound rather preposterous. Yet, one must remember that by a priori Wolff actually means all sorts of demonstrations, which can have empirical premisses. Indeed, Wolff appears to accept only actuality of something as an undemonstrated justification of it's possibility. Thus, we can learn that something is possible only by showing where to find or how to make it actual or by demonstrating it from the actual existence of something else.
What then are the possibilities and impossibilities according to Wolff? Simply put, we can think of them as lists of characteristics. Picture a huge paper full of descriptions like ”triangular”, ”round”, ”square”, ”humanoid”, ”animal”, ”mushroom”, ”pouty”, ”frivolous”, ”intelligent”, ”rioting” and infinitely many others. Circle some of these characteristics or determinations: if the set of characteristics is such that all its members can belong to a single entity, the set describes a possibility, if not, an impossibility. Note that we then have more and less detailed lists – a pair ”pyramid” and ”red” can be made more detailed by the inclusion of characteristic ”coppery”.
Now, if you are aiming at possible result, obviously circling some determinations will make it necessary to circle also other determinations. For instance, if we accept Euclidean geometry without further ado – and they did this back at Wolff's time – circling description ”triangular” forces us also to circle the description ”sum of angles equals two right angles”. The first characteristic, as it were, determines the second, or using terminology of the previous text, thing having this characteristic is a sufficient reason for it having that characteristic.
Let us now assume that we have chosen a set of characteristics, which are meant to define certain possible thing. This set forms then the essence of the supposed possibility (say, triangularity forms the essence of triangles). Clearly, changing any characteristics that is part of the essence would change the possibility (e.g. square wouldn't be a triangle anymore). In this sense essence is always constant for the possibility it corresponds to. This doesn't mean that e.g. triangular pieces of matter could not turn to square piece of matter: then this piece of matter just wouldn't correspond to the essence of triangularity anymore. In effect, when we speak of an essence of a thing, we must assume some viewpoint from which to decide what is essential and what not for the thing in question.
Note that just putting together characteristics does not produce an essence, because such a list does not necessarily refer to any possibility. What one must do is also to show the possibility of this set of characteristics. We have just seen that it is only through actuality that such a proof can be effected. In fact, we need what Wolff has called a real definition, that is, an account of how the thing to be defined can be generated.
Now, when we have determined an essence, clearly also those characteristics determined by the essence will be constant – they cannot change, unless the essence changes. Such determined constant characteristics Wolff calls attributes (note that it might be equally contextual what to takes as essence and what as attribute). Some of these attributes are shared by things with other essences – these Wolff calls common attributes – while others are proper only for the things with that essence.
While essences and attributes are constant for thing of a certain sort, there are characteristics that are not, that is, modes. Thus, triangle could continue being triangle, even if its colour would change. Clearly such a distinction between essential and non-essential characteristics depends on the perspective – while colour is not essential to a triangle, it would be to a green triangle. Furthermore, the modes are not completely separate from essential characteristics and attributes. In fact, some sets of possible modes (say, a set of possible colours of a triangle) clearly form an attribute of the thing in question (it is not necessary that a triangle has any particular colour, but it must definitely have some colour).
In addition to essential characteristics, attributes and modes, things also have relations to one another. A peculiar notion of Wolff, derived probably from Leibniz, is the conviction that all relations could be reduced to modes. In effect, this means that one need not discuss other things when dealing with one thing. Thus, while essential characteristics and attributes of a thing can be explained through one another, its modes can be grounded on its other modes, current or past – that is, all causal processes can be regarded as involving only one object at a time.
Wolffian sea of possibilities is then filled with such groupings of characteristics. Characteristics of one thing cannot clash with one another, or otherwise there wouldn't be any such thing. Yet, just by being a possibility, the thing still isn't actual – one must still add something to make it actual. Kant was later to criticize Wolff, because no addition of a new characteristic could make possibility into actuality. Yet, here Kant is clearly too harsh for Wolff, who knew that mere addition of characteristic would no difference, but ”something else” is required – what this something else, is purposefully left unsaid by Wolff at this point of discussion, although later on it becomes evident that it is the spark of God that makes everything actual.
So much for possibilities, next time I shall look at what Wolff has to say about identity.