Final answer:
The statement emphasizes the importance of gaining experience and subjecting it to intelligent development and direction in order to achieve profound understanding and expertise.
Step-by-step explanation:
The statement means that there is no discipline as rigorous as the discipline of gaining experience and subjecting it to the tests of intelligent development and direction. This implies that through hands-on experience and applying critical thinking skills, individuals can gain a deep understanding and mastery of a subject or field.
For example, in the field of science, scientists conduct experiments and collect data to gain knowledge and insights. By subjecting their experiences to analysis and interpretation, they can make meaningful discoveries and advancements. Similarly, in the field of literature, writers refine their skills through practice and critique, resulting in the development of their craft.
In summary, the discipline of experience, when combined with intelligent development and direction, can lead to a profound level of understanding and expertise in a particular subject or field.