Early socialists had a habit of describing their "perfect society", down to miniscule detail of how people would live their lives on a day to day basis. This society, of course, was the product of their heads, and prioritized imagination over reality. This is what makes it 'utopian', being impossible from inception. Later, 'scientific socialism' would be coined by Marx and Engels to describe their process of attempting to improve society through critical analysis of existing structures and social modes