4th post in the 5 post series on, ‘What is Morality?’
This is Our thoughts are a combination of negative and positive emotions.
What makes a mindset a positive or negative disposition is the imbalance between these two vibes: If a person is more inclined to optimism, then it’s right to say that he/she has positive vibes; lingering bitterness in someone’s attitude, on the other hand, reflects negativity of character.
Most people swing between the two vibes all through life.  
Now, to understand this further, let’s try this – say to yourself, ‘I shall win the lottery tomorrow.’ See if this prediction comes true the next day.
Next, say to yourself, ‘I don’t think I’ll get the promotion ( or anything else you might be contesting for) .’
Chances are that your second forecast may come true, and it is because most of us lack ‘belief’ in accepting that we deserve better than what we have. Not just that, one almost feels ‘relieved’ when negative predictions come true since pessimistic emotions seem so much more natural, easier, and plausible to us. One even develops immunity to frustrations in life and becomes defeatist.  
It’s a proven fact, at least according to the science of psychology, that we, the humans, have a proclivity for pessimism. And that’s why usually when someone thinks or says something negative it usually comes true. In other words, we attract negativity, and when it manifests believe more in its existence and its place in our lives. Many get caught up in this vicious circle.
So, when we talk about developing a positive mindset, what does it actually mean? Do positive vibes kill negativity to replace it altogether? Or, is it about tilting the balance?
To decide the answer, understand what does negative mind means, and equally, what a positive mentality feels like.
In the shortest possible version- The negative mind is what generates a ‘dim view’ of things, and the positive mind generates a favorable view of things.
If I had low self-esteem or in fact even overestimated myself, then my mindset would emit negative vibes because I would be out of sync with my real and potential self. Equally, if I am an optimist and am grateful for my glass being half-full, my mindset would be vibrating at a higher frequency of positivity.
Most of us go through ups and downs, good and bad, and dark and bright experiences in life. What makes our disposition positive or negative is how we deal with situations. Also, temperament is defined by how long one lingers in the same zone of emotion – some people have the propensity to feel sorry for themselves perpetually: the victims. They would spend their entire life being morose. Others refuse to accept defeat easily, and never cease to try to succeed: the fighters. This does not connotate that a glum face can never manage to smile, or a heartening person couldn’t be disheartened sometimes.
So, to change negative thinking into positive vibrations would mean tilting the balance more towards optimism and hope. Also, to be negative about negativity too is positive.