CL 528, 529 - purposefully or deliberately

CL 528
It is said in the church
that . . . anyone who sins 
against one commandment of the Decalogue 
sins against them all. 
But this conventional maxim is not as it sounds;
for it is to be understood in this way,
that anyone who purposefully or deliberately acts
against one commandment
acts against the rest,
since to act purposefully or deliberately
is to deny altogether that the action is a sin,
and anyone who denies the existence of sin
regards it as nothing
if he acts against the rest of the commandments.

CL 529
Something similar is true in the case of people
who are in a state of good from the Lord. 
If they from their will and intellect
or purposefully and deliberately
refrain from one evil because it is a sin,
they refrain from them all;
and this still more if they refrain from several.
For as soon as anyone
purposefully or deliberately refrains 
from some evil because it is a sin,
he is kept by the Lord in a purpose
to refrain from the rest.