Griffin as a scientist was brilliant. He had found a way by which a human can become invisible. He himself became invisible a number of times and his experiment was a huge hit. His invention could have been used for the welfare of science as well as the mankind if he used it in a proper way but he chose to use his invention for his own selfish needs.
He always used his own invention for mischief. He never used it for anything good. He used it a number of times to escape from being chased and for stealing. All these things show that he was a great scientist but a pathetic human.