Would probably bump this up a star for the average reader, but for someone who is more familiar with psychology and self help, only 3 stars.
First, David Seabury allows his bias to influence his work slightly (for instance, I believe he overstates and too broadly for the case of love in his earlier chapters, as well as some overstated analogies both christian-based and non-religious) but he redeems himself by presenting a collection of factual and practical details that should help average readers, as well as how to change for the better.
He generally has a good flow to his book. This includes reducing/eliminating fear by directing attention to things that can be acted on (such as devotion to a worthy cause), the usefulness and power of positive thinking, not overwhelming yourself and others about your anxieties, discussion on how fear produces rage as a survival instinct (and how negativity such as hatred forms into a vicious cycle) with ways to reduce it, using knowledge to overcome fear, and how the imagined self can influence & focus will for a better life outcome.
He also offers very specific techniques, both as analogies and practices that help readers better cope with inadequacies driven by fear. His book contains one of the better examples I've seen to making positive thoughts active (dynamic) opposed to being generalized. Quoting a section from his work:
"Dynamic: Attention is as important as breathing. I refuse to keep my attention on the unkind thing Mary said. Undynamic: I forgive Mary for her remark."
He also includes a section on psychosomatic medicine for health and generally staying level-minded to support his positive thinking argument. As unbelievable as it sounds (as I have found it to be the case in research prior to reading his book), there are instances of people who optimistically believe something bad will not happen (either assisted by hypnosis or by their own volition, such as not getting a cold) will generally express greater health in adverse situations. Additionally, he argues the increase of negative thoughts and beliefs that something may occur can further deteriorate health. In summary, we create our reality for the better or the worse, so why not just aim for better?
I find this book too non-specific to aid in scientifically-oriented inquiry, but it is noteworthy to see a book written more than 50 years ago conforms to recommendations on self-help and ambition we use today.