Well what i interpret of this quote is
Here Durkheim is trying to say that the environment which we live in according to us is consist of forces, constraints that stops us from doing things, alter our behavior but these forces that block us is the one we have created by ourselves. We are the society we have created these norms and values and we are blocked by it.

but the theory of social fact that Durkheim gave is it is referring to facts, concepts, expectations that come not from individual responses and preferences, but that come from the social community which socializes each of its members.

if we see the quote it supports the fact that the forces are created by the individual and we individual are the society.

Now here let me know if i am wrongly interpreting the Quotation or not? THANK U

What are the forces then that he has mentioned that exist in our mind?