Definition of Conscience

Conscience...means
acknowledging man,

oneself and others,

as created, and

respecting the Creator

in his creation.

That sets a limit to all power and at the same time gives it a direction.
Consequently perseverance in the powerlessness of conscience remains the fundamental condition and innermost core of all true control of power.

Where this innermost core is not maintained, there can no longer be any question of the control of power, but simply of a balance of interests in which man and human society are reduced to the model of natural selection: good is what prevails; to exist means to survive.
Man no longer lives as a creation but as a product of natural selection, and the power which he set out to control becomes his sole criterion.
His humanity is destroyed.

Benedict XVI, Joseph Ratzinger in Communio Vol. 2 Anthropology and Culture, p.19

Ratzinger indicates two essential elements in the human conscience

1. To acknowledge man (every human person) as a creature.
2. To respect the Creator in his creation (which therefore includes each and every person).

N.B. An "Examination of Conscience" seems to be an almost exclusively Catholic spiritual exercise, essential for Lent and for any true repentance. Inventory of the soul! How am I doing with God?