Answer: he believes that the actions of human beings are often driven by greed and convenience.
Step-by-step explanation:
Former senator George Vest said the words above when he was a lawyer for a person who was suing another for killing his dog. In the statement we can infer that Vest thinks that human actions are driven by greed and convenience unlike that of a dog which is driven by love and devotion.
Humans tend to desert another when times are tough and riches disappear and they only engage in actions that will benefit them as well. It is different for dogs as they will even stay when their masters are poor and unable to feed them. This is the point that Vest was trying mke.