Logic- Chapter 1

This argument is invalid: All men are mortal. Knachel is mortal. Therefore, Knachel is a man. Its logical form looks like this: All As are Bs. x is a B. Therefore, x is an A. where A and B stand for groups of things, and x stands for an individual thing. Which of the following suffices to demonstrate the invalidity of this argument?

All whales are mammals. Knachel is a mammal. Therefore, Knachel is a whale.

Choose the tacit premise that the author needs to make this argument go through: We need to reverse the flow of manufacturing jobs overseas; we should provide tax breaks to companies who do their manufacturing in America.

Tax breaks for companies who manufacture in America would discourage outsourcing of manufacturing jobs to overseas plants.

Consider these two passages. Are they more likely to be arguments or explanations? 1. Late-term dilation and extraction abortions (called "partial-birth abortions" by those who oppose the practice) are a flashpoint in the abortion debate. Many argue that its advantages make it an indispensible option for many mothers: it avoids risky surgeries and expensive hospitalizations; and in cases of hydrocephalus (over-sized fetal cranium) it can be the only viable alternative. Opponents say it's tantamount to infanticide, as it involves removing the fetus, then terminating it; and they point to the graphic, gory nature of the procedure to label it barbaric. [Context: Newspaper article reporting on a bill pending in the legislature to ban late-term abortions] 2. The fifty-five mile per hour speed limit is an anachronism. Today's lighter, fuel-efficient, safety-checked automobiles are more than capable of handling highway speeds much higher. Moreover, lower speed limits only make the problem of long commute-times worse. [Context: speech by a member of the legislature about a bill to raise the speed limit to 70 mph]

1 is an explanation; 2 is an argument.

What is the conclusion of this argumentative passage? I'm the meanest man that ever had a brain,All I scatter is aches and pains.I'm carbolic acid, and a poison face,And I stand flat-footed in favor of crime and disgrace.If I ever done a good deed -- I'm sorry of it.

I'm the meanest man that ever had a brain.

Consider this inductive argument: Knachel cuts his own hair. Knachel still drives a rusty, beat-up 1990 Oldsmobile. Therefore, Knachel is poor. Which of the following, if added as an additional premise, would most weaken this inductive argument?

Knachel is an avid collector of rare gold coins.

Which of the following is the best explication of the following argument? You can't seriously be saying that school teachers need unions to protect them. Teachers don't work for greedy capitalists; they work for the public. Do they need protection from the public?

Premise: Teachers don't work for greedy capitalists. Premise: Teachers work for the public. Premise: Teachers don't need protection from the public. Conclusion: Teachers don't need unions to protect them.

What tacit conclusion follows most immediately from the following passage? If the mayor really wanted to improve quality of life in the city, he wouldn't have cut funds from the Parks Department.

The mayor doesn't really want to improve quality of life in the city.

What's the conclusion of the following argumentative passage? 47 million people are without healthcare in this country. And with a recession on that number will only grow. We must enact healthcare reform now. It is a moral imperative for a wealthy nation to provide access to healthcare for all its citizens. If we don't act now, the rising cost of healthcare will bankrupt the country.

We must enact healthcare reform now.

What is the conclusion of this argumentative passage? Unregulated speculative activity by large banks led to the financial crisis of 2008. Such firms continue to engage in risky behavior. We need new bank regulations now. If we don't rein Wall Street in, we'll have another crisis soon.

We need new bank regulations now.

An argument with true premises and a true conclusion is:

impossible to evaluate without more information