Lateral thinking is a concept developed by Edward de Bono. It involves a way of thinking that does not adhere to the typical step-by-step thinking following a logical order. Our brains are conditioned to think in a straight-forward manner. It takes deliberate effort to do some kind of lateral thinking to arrive at a conclusion or solve a problem. Traditional thinking is more vertical, where each thought is connected or related to the next one following some logic. Edward de Bono argues that thinking happens in 2 stages. The first stage is a perceiving stage, where the brain sets the environment, the constraints to think under. And the second stage, where the brain uses the environment to arrive at a conclusion.
He has also described 4 ways to practice deliberate lateral thinking: