Book III - Chapter VII Of Particles 1.
Particles connect parts, or whole sentences together.
Besides words which are names of ideas in the mind, there are a great many others that are made use of to signify the connexion that the mind gives to ideas, or to propositions, one with another. The mind, in communicating its thoughts to others, does not only need signs of the ideas it has then before it, but others also, to show or intimate some particular action of its own, at that time, relating to those ideas. But besides affirmation or negation, without which there is in words no truth or falsehood, the mind does, in declaring its sentiments to others, connect not only the parts of propositions, but whole sentences one to another, with their several relations and dependencies, to make a coherent discourse. In right use of particles consists the art of well-speaking. They show what relation the mind gives to its own thoughts.