Does the transition from the first to the second jhana happen automatically, or does one make a conscious change?
It’s a bit of both, because this is explaining the transition between the first level of meditation and the second. The jhanas – the levels of meditation – are a road map that the Buddha gave us. If we use Right Effort, if we use Wise Practice – Samma Vayama – we will go through these states naturally. But to be aware and to understand them, will help us as well to understand how to practice. Then, there is more confidence and we understand where this is going, instead of constantly wondering.
At the beginning, there will be thinking, there will be imagining. It might be that you are using this to bring up, for example Joy, or an uplifting object, because when the mind is uplifted and happy, it is aware. The nature of a joyful mind is to be aware and not overexcited, just uplifted, just happy.
When this happens, as you continue calming down, letting go – whatever your object of meditation is, whether you’re using the Loving-kindness, the Compassion or the Satipatthanas – it will calm down. The thinking and the reflection will naturally become too coarse for the mind. The mind will start to really collect and gather, and these thoughts and imagination will feel like restlessness a little bit more. So, naturally, that is simply your wisdom, your discernment that is getting sharper and sharper. And the mind is taking more delight, more freedom in not thinking.