constitute

To say that we need to curb anger and our negative thoughts and emotions does not mean that we should deny our feelings. There is an important distinction to be made between denial and restraint. The latter constitutes a deliberate and voluntarily adopted discipline based on an appreciation of the benefits of doing so. This is very different from the case of someone who suppresses emotions such as anger out of a feeling that they need to present a facade of self-control, or out of fear of what others may think. Such behaviour is like closing a wound which is still infected. We are not talking about rule-following. Where denial and suppression occur, there comes the danger that in doing so the individual stores up anger and resentment. The trouble here is that at some future point they may find they cannot contain these feelings any longer.

What does constitute mean?
What does 'out of a feeling that' mean?
What does 'in doing so' refer to?
What does 'we are not talking about rule-following' mean?