The issue with democratic systems versus a republic or a constitutional monarchy, whereas there is a Magna Carta, or otherwise any guaranteed protection of the people's rights is that it can be voted away to a majority.
An unelected king that has total control over his subjects with no restraint of power or protection for the people will make none the difference but that in a democracy that person was elected to have total control over his subjects.
The disadvantage, or advantage, of a democracy, is that the majority will always rule over the minority. Regardless of there protected rights.
It was rejected since he suggested that the acquired character which was an organism gain through its life experiences are transferred to its next Generation