Over the last couple of weeks I have spent the evenings studying with the Social Care Institute for Excellence. In order to support my clients I wanted to gain a greater understanding of the Mental Capacity Act 2005 in order to advocate with and for them. Principles of the Mental Capacity Act 2005 1. You must assume a person has capacity unless it is established they lack capacity. This should not be based on behaviour, age, health condition etc. Capacity is decision and time