This quote emphasizes the importance of instinct and innate goodness over a misguided moral compass. A ‘sound heart’ refers to a person’s inherent sense of right and wrong, their gut feelings, and their natural instincts. It suggests that these intrinsic values are a more reliable guide in life than an ‘ill-trained conscience,’ which could be influenced by external factors such as societal norms, cultural conditioning, or personal biases.

An ‘ill-trained conscience’ implies a sense of morality or ethics that has been poorly developed or distorted. It might lead a person to make decisions that are technically ‘right’ according to certain standards but feel wrong on a deeper, more intuitive level. Twain suggests that it’s better to trust our innate sense of justice and kindness than to rely solely on learned concepts of morality, which might be flawed or misguided.

Applying this idea to today’s world or personal development, it could be interpreted as a call to listen to our hearts and trust our instincts more. In a world where we’re constantly bombarded with information and opinions, it’s easy to lose touch with our inner guidance system. We might be swayed by popular opinion, societal pressure, or the desire to fit in, even when these things conflict with our true feelings.

In terms of personal development, this quote encourages us to cultivate our inner wisdom and listen to our hearts. It suggests that true growth and wisdom come from aligning with our authentic selves, rather than conforming to external expectations or standards of morality. It’s about trusting ourselves, even when our instincts go against the grain.

In essence, this quote is a reminder to stay true to ourselves and our values, to listen to our hearts, and to trust our instincts. It’s about recognizing the inherent wisdom and goodness within us and using that as our guide in life.