Energy is the ability or capacity to produce an effect. It also denotes the power or resources needed to make a change.
Apart from ordinary usage (especially in MSI) Alexander applies the term to the use of the self. It would appear that with energy, as with attention or directions, the question is not one of ‘creating’ more, but of developing a more efficient use of what is available.
It is in UoS that Alexander makes most frequent use of the term ‘energy’ as applied to the self, e.g. in chapter 1, the ‘conduction of energy’ is what makes the difference between merely thinking of something in an abstract way and effecting a change:
When I employ the words ‘direction’ and ‘directed’ with ‘use’ in such phrases as ‘direction of my use’ and ‘I directed the use,’ etc., I wish to indicate the process involved in projecting messages from the brain to the mechanisms and in conducting the energy necessary to the use of these mechanisms.
If energy provides the messages with their affirmative action, lack of energy can equally disconnect messages: later in this article, inhibition is described as cutting off the energy. This usage also appears in UoS (chapter 4) when Alexander describes the process of change:
(1) the inhibition of the instinctive direction of energy associated with familiar sensory experiences of wrong habitual use, and (2) the building-up in its place of a conscious direction of energy through the repetition of unfamiliar sensory experiences associated with new and satisfactory use.
In UCL he specifically mentions ‘nervous energy’, i.e. neural activity:
… if we project those messages which hold in check the familiar habitual reaction, and at the same time project the new messages which give free rein to the motor impulses associated with nervous and muscular energy along unfamiliar lines of communication, we shall be doing what Dewey calls ‘thinking in activity.’ (Chapter 5, part ii).