A thing is said to be finite in its own kind [in suo genere finita] when it can be limited by another thing of the same nature. For exampole, a body is said to be finite because we can always conceive of another body greater rhan it. so, too, a thought is limited by another thought. But body is not limited by thought, nor thought by body.
Spinoza, Ethics, the second definition
Before we say about a thing that it is limited in its kind or genus, we approach it in relation to its genus.
A relation that is not marked off by an opposition or a difference, but, on the contrary, it is a sort of agreement. A thing ascribed to a genus is primarily in agreement with its genus. What sort of agreement? Not that tensionate agreement that is supposed when we think of a genus as subduing its species. It is rather that agreement claimed for memebers of the same family, close to Wittgenstein’s idea of a family ressemblance between things. For genus is derived from the Greek words that designate ‘birth’ and the ancestry ensued from the birth of one man.
The members of a family know that behind them it is something that tie them together, though each of them acts individually. It is not a tie that denies their individuality, as we always are bent to conceive the relation of a genus with its species. It is that stable point forgotten in the course of movable actions of an individual, but always there, in the same place. For this reason, at least Homeric heroes remember their family by its place of dwelling. In an individual person or thing, the genus seems to count for what remains unaltered after the continuous dissipation of the individual in various actions. For the man, the corpse is not only a dead matter, but also that stable part of a man that allows someone to read the signs of the human kind. And, as we put the corpse away from the conception of a living man, so we do as regards the relation of things with their genus, every time when we do not speak about them. Before we recall that a table is to be called as a table, we use it with the back thought that is something in it that makes it a stable and definite object. Who does use a table with the thought that it is just the object he uses and not anything else apart from its current use?
Therefore, when we put the theoretical question of the inclusion of a thing in its genus, we are already far from the common dealing with things in that unspoken way that reveals the genus as a durable part with which thing shares the closeness of belonging to a family.
And it is a theoretical question, as much it is a spoken one: ‘a thing is said to be finite…’. The language is responsible for the transformation of the relation between a thing and its genus as one that signifies a strength difference between them, even an opposition, best known when we definitionaly establish the difference between the things that belong to the same genus.
The clarification brought by language has the costs of a reluctance interposed between things and also between things and man who knows them. As a consequence, things appear with rigid limits and we are tented to conceive them as being enclosed in their individuality and merely overruled by a genus, as there is graphically represented in a tree of classification. Surely, since we speak about things in this way, they really are so for us.
As Spinoza claims, the things spoken come to show their finitude. Our language exercises itself in limiting the realities discussed, and also the community of speakers, since language is spoken by someone as he is a different person than others and often with the purpose of imposing a belief or an idea to others deemed to be lesser in the same community of speakers. ‘A thought is limited by other thought’ primarily because the thought is expressed through language and it is in the property of one speaker. There is not a syllogistic order of premises and conclusions mutually limited, when we thought of a state of facts or of a thing without speaking loud what we take in consideration.
In the moment we accept that things are not to be found in the opposition provided by the language, we surpass the practice of including them under the leadership of a genus. They are free for being together, for Spinoza, as there is the case of thought and body. For instance, the difference between the thought of a table and its bodily existence becomes futile. Or, we are also entitled to say that the difference between men’s thought and body is not as deep as the language makes us to believe. The fact that each belongs to a different genus does not necessary involves that, for instance, the movement of body and the development of thoughts do not merge each other for constituting one resemblance of family as strong as that supposed by their unspoken relation to their own genera or kinds.