I think he may be referring to the development of culture (the collective mindset and consequent products of a social group) through communication.

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

What are the forces then that he has mentioned that exist in our mind? — samay bin tahir

Reactions to intersubjective mental representations and social context?

Take money, for example. What a lot of time we spend exchanging little bits of metal and paper. Or marriage, or nation,

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

Yes. There are forces that give importance to these bits of metal and paper, such that the individual cannot find food or shelter without them. I like to have money, I believe in the value of money because the nice people at Asda collect it, and will give me food if I bring them some. And they collect it, and value it because they can do stuff with it because everyone else likes to collect it, and so round and round. But apart from our belief, known to economists as 'confidence', it has no value to anyone of itself. It is a huge force that dominates our lives, but it is constructed in our minds.

A passport is another magic piece of paper that allows one to cross a magic line on the ground that is guarded by special people who do it all day and night. Both the line and the magic paper have existence only in our minds, cats ignore them completely.

To do sociology, one has to try and recognise these forces that impinge on one's own world, and not mistake this for some kind of 'primitive' condition that sociologists are immune from. This is why I tried to steer you away from 'religion', as if we sophisticates can manage without such things. The rules of the road, the whole of the law, are things of the mind that we have to believe in because everyone believes in them; and without that belief, and the actions that flow from it, they have no existence.

This is why I tried to steer you away from 'religion', as if we sophisticates can manage without such things. — unenlightened

Are you saying society is a religion?

No. We're talking about social facts.

My interpretation of Durkheim's idea of "our social environment is filled with things only real in our minds", is that society is built and structured by ideologies/institutions that are not necessarily "real"...for example, a business is considered a separate entity other than the people or person who own the company/work it, etc. The company is not an actual living being, but we have created meaning to it by calling and treating it as a being.
The earlier examples of passport and money are wonderful as well... WE as humans add meaning to these ideas and objects.
Society is only constructed from our projected ideas / meanings