There is no positive or negative thinking. There is only thinking. Engaging in only positive or only negative thinking is just half thinking. It is a judgement placed on your thinking.
Everything just IS, whether it is positive or negative depends on our perspective, the meaning we give it, emotions that it brings in us. Also, on what we think it should be, what we want it to be, or our preference.
For a holiday maker thinking that it is going to rain tomorrow is negative, however for a farmer it could be very positive.
I could never understand why saying “the glass is half full” is optimistic (positive) and “the glass is half empty” is pessimistic (negative). What is in the glass? Do I want it to be full or empty?
If it is medication for a child and they need to drink it; wouldn’t a statement, “the glass is half empty” be more optimistic. What if it has some sticky gunk in it that I am trying to get out? Is it still optimistic to say it is half full?
Yet, people make this judgement without really thinking about it. They must be using the unexamined assumption that more is better. This is assumption is so imbedded in our psyche that we subconsciously perceive and judge “more”, “full” as better. It one of the most powerful assumptions that drives our consumption
Everything in life depends on duality; without positive and negative there will be no electricity, no magnets. What you consider negative may be positive for someone else. Rejecting what you do not like or consider not favourable and labelling it as negative, stops you from thinking about it.
Because you do not want to be negative, you make a judgment without thinking.
However, would you cross the road without looking if there is a car coming and label the thought about checking it as negative. I do not think so.