Supernatural and Atheism

[Jehanne]

As energy is equivalent to mass, loading software into a computer will slightly increase its total energy, and, hence, its total mass.

In that case a body with a soul (in the Aristotelian definition) would have slightly more mass, because it is the soul which regulates all the body's activities, including all kinds of energy use. Without the soul energy use ceases (i.e. the body dies). 

So the soul is still immaterial, and has no mass of its own, but is the cause of increased mass in the body.

The experiment of weighing the soul was performed a century ago -- 21 grams was the result. The experiment has, however, failed upon replication.