  In this talk we discuss some of the main theoretical problems in the
understanding of the statistical properties of gravity. By means of N-body
simulations we approach the problem of understanding the r\^ole of gravity in
the clustering of a finite set of N-interacting particles which samples a
portion of an infinite system. Through the use of the conditional average
density, we study the evolution of the clustering for the system putting in
evidence some interesting and not yet understood features of the process.
