And this restraint almost necessarily, though not absolutely so, produces vice.
Yet in all societies, even those that are most vicious, the tendency to a virtuous attachment is so strong that there is a constant effort towards an increase of population.

This constant effort as constantly tends to subject the lower classes of the society to distress and to prevent any great permanent amelioration of their condition.
The way in which, these effects are produced seems to be this.

We will suppose the means of subsistence in any country just equal to the easy support of its inhabitants.

The constant effort towards population, which is found to act even in the most vicious societies, increases the number of people before the means of subsistence are increased.

The food therefore which before supported seven millions must now be divided among seven millions and a half or eight millions.