Summary of the article Mariarty (2001) main thesis is that modern-day engineers need to move beyond know what or know how, and embrace know-why. Contemporary engineering must be governed by three types of ethics that emerge from different eras of engineering: virtue ethics, conceptual ethics and material ethics. The latter are synonymous with traditional engineering, modernist engineering and focal engineering, respectively. The author starts with a description of the earliest form of engineering, which was traditional engineering. At the time, engineers lacked a central scientific method with which to carry out their work. Therefore, most of them depended upon their intuition and experience. Since they worked under autocratic leaders, they had little room to inquire into the processes of production. They merely implemented what they were told using rough estimates. As a result, the actor was the most important component of the engineering process. This meant that ethical principles that governed a person’s character were the most appropriate. Virtue ethics stresses the importance of doing good. A person strives to be honest, caring and diligent in his or her method. Therefore, the traditional engineer compensated for the lack of scientific expertise using his character. Such a person was diligent, hardworking and even-tempered. This aspect of ethics is still applicable today as stakeholders still want to know about the actor. Know-what is still imperative in engineering practice. Modernist engineering was the next phase of development in the profession. This saw the birth of scientific processes in engineering. Stakeholders were not just concerned about the actor but now dwelt on the act. They moved from know-what to know-how. Analysis and synthesis now became central elements of the engineering process. Therefore, the brand of ethics developed for this type of work was material ethics. Individuals developed ethical frameworks that would justify why it was necessary to do good. At the time, individuals such as Johns Stuart Mill and Immanuel Kant came up with conceptual ethics. Mill was the father of utilitarianism, which stressed the need to maximise the overall good for the greatest number of people. Kant created the Categorical Imperative, which prompted people to act as though, if they were in the same position, they would do the same. Conceptual ethics is a brand that stemmed from technicism. Technicism is a school of thought which espouses that man should control his reality as he has the capacity to do so. The final phase of this profession was focal engineering. It dwells on things that enrich people’s life. There, the main concern is not just to produce, but to add value to people’s lives. At this point, the actor’s role seemed to subside and more emphasis was given to the product hence the need for material ethics. Material ethics asks questions regarding the effect of the product on the concerned stakeholders or environment. The focal engineer is one who looks at the reasons, purposes and causes behind certain things. He or she causes engagement between the user and product, harmony between the beneficiary and the world and harmony between the world and the products. It shifts away from know-ho