I agree with Samuel Bostaph. Populace act consciously but they can 
not predict the final result of their actions. Any official rule to 
be effective must have roots in the behavior of individual agents 
pursuing their own ends (see Menger and Hayek). At some point, 
particular convention desired for their properties become so 
widespread that they take on the status of an institution. So first 
they emerge endogenously and without a supreme action. It doesn't 
mean that some institutions appeared like spontaneous orders remains 
unchanged. A spontaneously emerged convention can evolve into a 
official rule of conduct with a spontaneously emerged convention in its core.

Rustam Romaniuc