He was a very compassionate and humane person.
He felt for the sufferings of other people of all walks of life and was prepared to give his money and his time and influence to help to alleviate those sufferings.
He was selfless.
He became a Member of Parliament in order to help others. He did not benefit personally or financially from his campaigns. He did not take up campaigns that reflected concerns in his own life or circumstances but fought for the poor and oppresed both at home and abroad, usually for people he would never meet.
He was a man of vision.
Many of his ideas and beliefs (e.g. all people, of whatever race, should be treated equally, and the death penalty should be abolished) were way ahead of his time.
He was very dedicated to his causes.
For example, he worked so hard trying to get slavery abolished, that he became ill.
He was a champion of justice and fairness.
He campaigned against the injustice of people being put to death for petty crimes, of Indian widows being burnt on their husbands' funeral pyres, of Africans being turned off their own lands by European invaders and of people being enslaved by others.
He never sought glory despite his endless efforts.
A friend wrote that Thomas put himself entirely out of the question. "It does not seem to excite any feeling in his mind whether after all his toils he is to appear in the matter or not. He seems to care for nothing but the advancement of the cause".
He was very independent and followed his own conscience.
He would not join any party in parliament and would vote for exactly what he thought was right and not for what others wanted. Even if that meant he became unpopular and caused him distress as he hated hurting his friends.
He was an honest man and had integrity and honour.
He stuck to what he thought was right despite great pressure from others on both sides of the abolition campaign. In elections he refused to use dirty tactics or to pay for votes even when he knew it would lose him the election.